C程序设计(第三版)课后题答案

习题答案

第一章 1.5

# include void main()

{

printf(\"* * * * * * * * *\\n Very good!\\n* * * * * * * * *\\n\"); }

1.6

（法一） #include main() {

int a,b,c,max;

scanf(\"%d,%d,%d\max=(a>b)?a:b;

max=(max>c)?max:c; printf(\"max=%d\\n\}

（法二）

main() {

int a,b,c,max;

scanf(\"%d,%d,%d\if(a>b&&a>c) max=a; else if (b>c) max=b; else

max=c;

printf(\"max=%d\\n\}

（法三） # include void main()

{

int max(int x,int y,int z); int a,b,c,d;

scanf(\"%d,%d,%d\d=max(a,b,c); printf(\"max=%d\\n\}

int max(int x,int y,int z) { int A,B; if(x>y) A=x; else A=y; if(z>A) B=z; else B=A; return(B); }

第三章 3.3

(1)(10)10=(12)8=(a)16 (2)(32)10=(40)8=(20)16 (3)(75)10=(113)8=(4b)16

(4)(-617)10=(176627)8=(fd97)16 (5)(-111)10=(177621)8=(ff91)16 (6)(2483)10=(4663)8=(963)16 (7)(-28654)10=(110022)8=(9012)16 (8)(21003)10=(51013)8=(520b)16 3.6

aabb (8)cc (8)abc (7)AN 3.7 main()

{char c1='C',c2='h',c3='i',c4='n',c5='a'; c1+=4, c2+=4, c3+=4, c4+=4, c5+=4; printf(\"%c%c%c%c%c\\n\} 3.8 main()

{int c1,c2; c1=97;c2=98;

printf(\"%c %c\

} 3.9 (1)=2.5 (2)=3.5 3.10 9,11,9,10 3.12

(1)24 (2)10 (3)60 (4)0 (5)0 (6)0

第四章 4.4 main() {int a,b,c; long int u,n; float x,y,z; char c1,c2; a=3;b=4;c=5;

x=1.2;y=2.4;z=-3.6; u=51274;n=128765; c1='a';c2='b';

printf(\"\\n\");

printf(\"a=%2d b=%2d c=%2d\\n\

printf(\"x=%8.6f,y=%8.6f,z=%9.6f\\n\,z);

printf(\"x+y=%5.2f y+z=%5.2f z+x=%5.2f\\n\,y+z,z+x); printf(\"u=%6ld n=%9ld\\n\printf(\"c1='%c'or %d(ASCII)\\n\printf(\"c2='%c'or %d(ASCII)\\n\} 4.5 57 5 7

67.8500,-7.123962 67.8500,-7.123962

67.86 -7.12,67.8500,-7.123962,67.8500,-7.123962 6.7850e+001,-7.e+002 A,65,101,41

1234567,4553207,d687 65535,177777,ffff,-1

COMPUTER, COM 4.6

a=3 b=7/

x=8.5 y=71.82/ c1=A c2=a/

4.7

10 20Aa1.5 -3.75 +1.4,67.8/

(空3)10(空3)20Aa1.5(空1)-3.75(空1)(随意输入一个数），67.8回车 4.8

main()

{float pi,h,r,l,s,sq,sv,sz; pi=3.1415926;

printf(\"input r,h\\n\"); scanf(\"%f,%f\l=2*pi*r; s=r*r*pi; sq=4*pi*r*r; sv=4.0/3.0*pi*r*r*r; sz=pi*r*r*h;

printf(\"l=%6.2f\\n\printf(\"s=%6.2f\\n\printf(\"sq=%6.2f\\n\printf(\"vq=%6.2f\\n\printf(\"vz=%6.2f\\n\} 4.9 main() {float c,f; scanf(\"%f\c=(5.0/9.0)*(f-32); printf(\"c=%5.2f\\n\}

4.10

#include\"stdio.h\" main() {char c1,c2;

scanf(\"%c,%c\putchar(c1); putchar(c2);

printf(\"\\n\");

printf(\"%c%c\\n\}

第五章 5.3

(1)0 (2)1 (3)1 (4)0 (5)1 5.4 main() {int a,b,c;

scanf(\"%d,%d,%d\if(aif(bprintf(\"max=%d\\n\ else

printf(\"max=%d\\n\else if(aprintf(\"max=%d\\n\else

printf(\"max=%d\\n\}

main()

{int a,b,c,temp,max;

scanf(\"%d,%d,%demp=(a>b)?a:b; max=(c>temp)?c:temp; printf(\"max=%d\} 5.5 main() {int x,y; scanf(\"%d\if(x<1)y=x;

else if(x<10)y=2*x-1; else y=3*x-11; printf(\"y=%d\}

5.6 main()

{int score,temp,logic;

char grade;

logic=1; while(logic)

{scanf(\"%d\

if(score>=0&&score<=100)logic=0; }

if(score==100) temp=9; else

temp=(score-score%10)/10; switch(temp)

{case 9:grade='A';break; case 8:grade='B';break; case 7:grade='C';break; case 6:grade='D';break; case 5: case 4: case 3: case 2: case 1:

case 0:grade='E';

}

printf\"score=%d,grade=%c\} 5.7 main()

{long int num;

int indiv,ten,hundred,thousand,ten_thousand,place; scanf(\"%ld\if(num>9999) place=5; else if(num>999) place=4; else if(num>99) place=3; else if(num>9) place=2; else place=1;

printf(\"place=%d\\nen_thousand=num/10000;

thousand=(num-ten_thousand*10000)/1000;

hundred=(num-ten_thousand*10000-thousand*1000)/100; ten=(num-ten_thousand*10000-thousand*1000-hundred*100)/10; indiv=num-ten_thousand*10000-thousand*1000-hundred*100-ten*10;

switch(place)

{case 5:printf(\"%d,%d,%d,%d,%d\\n\ printf(\"%d,%d,%d,%d,%d\\n\

break;

case 4:printf(\"%d,%d,%d,%d\\n\ printf(\"%d,%d,%d,%d\\n\ break;

case 3:printf(\"%d,%d,%d\\n\ printf(\"%d,%d,%d\\n\ break;

case 2:printf(\"%d,%d\\n\ printf(\"%d,%d\\n\ break;

case 1:printf(\"%d\\n\ printf(\"%d\\n\ } } 5.8

main() {long i;

float bonus,bon1,bon2,bon4,bon6,bon10; bon1=100000*0.1; bon2=bon1+100000*0.075; bon4=bon2+200000*0.05; bon6=bon4+200000*0.03; bon10=bon6+400000*0.015; scanf(\"%ld\

if(i<=1e5)bonus=i*0.1;

else if(i<=2e5)bonus=bon1+(i-100000)*0.075; else if(i<=4e5)bonus=bon2+(i-200000)*0.05; else if(i<=6e5)bonus=bon4+(i-400000)*0.03; else if(i<=1e6)bonus=bon6+(i-600000)*0.015; else bonus=bon10+(i-1000000)*0.01; printf(\"bonus=%10.2f\}

main()

{long i;

float bonus,bon1,bon2,bon4,bon6,bon10; int branch;

bon1=100000*0.1;

bon2=bon1+100000*0.075; bon4=bon2+200000*0.05; bon6=bon4+200000*0.03; bon10=bon6+400000*0.015; scanf(\"%ld\branch=i/100000;

if(branch>10)branch=10;

switch(branch)

{case 0:bonus=i*0.1;break;

case 1:bonus=bon1+(i-100000)*0.075;break; case 2:

case 3:bonus=bon2+(i-200000)*0.05;break; case 4:

case 5:bonus=bon4+(i-400000)*0.03;break; case 6: case 7

case 8:

case 9:bonus=bon6+(i-600000)*0.015;break; case 10:bonus=bon10+(i-1000000)*0.01; }

printf(\"bonus=%10.2f\} 4.9 main() {int t,a,b,c,d;

scanf(\"%d,%d,%d,%d\if(a>b){t=a;a=b;b=t;} if(a>c){t=a;a=c;c=t;} if(a>d){t=a;a=d;d=t;} if(b>c){t=b;b=c;c=t;} if(b>d){t=b;b=d;d=t;} if(c>d){t=c;c=d;d=t;}

printf(\"%d %d %d %d\\n\} 5.10 main()

{int h=10;

float x,y,x0=2,y0=2,d1,d2,d3,d4; scanf(\"%f,%f\

d1=(x-x0)*(x-x0)+(y-y0)*(y-y0); d2=(x-x0)*(x-x0)+(y+y0)*(y+y0); d3=(x+x0)*(x+x0)+(y-y0)*(y-y0); d4=(x+x0)*(x+x0)+(y+y0)*(y+y0); if(d1>1&&d2>1&&d3>1&&d4>1)h=0; printf(\"h=%d\}

第六章 循环控制 6.1

main()

{int a,b,num1,num2,temp;

scanf(\"%d,%d\

if(num1b=temp;} printf(\"%d\\n\

printf(\"%d\\n\} 6.2

#include\"stdio.h\" main()

{char c;

int letters=0,space=0,digit=0,other=0; while((c=getchar())!='\\n')

{if(c>='a'&&c<='z'||c>='A'&&c<='Z') letters++; else if(c==' ')space++;

else if(c>='0'&&c<='9')digit++; else other++; }

printf(\"letters=%d\\nspace=%d\\ndigit=%d\\nother=%d\\n\}

6.3 main()

{int a,n,count=1,sn=0,tn=0; scanf(\"%d,%d\while(count<=n) {tn+=a; sn+=tn; a*=10; ++count; }

printf(\"a+aa+aaa+...=%d\\n\} 6.4

main()

{float n,s=0,t=1; for(n=1;n<=20;n++)

{t*=n; s+=t; }

printf(\"s=%e\\n\} 6.5

main()

{int N1=100,N2=50,N3=10; float k;

float s1=0,s2=0,s3=0;

for(k=1;k<=N1;k++)s1+=k; for(k=1;k<=N2;k++)s2+=k*k; for(k=1;k<=N3;k++)s3+=1/k; printf(\"s=%8.2f\\n\} 6.6 main() {int i,j,k,n;

for(n=100;n<1000;n++)

{i=n/100; j=n/10-i*10; k=n%10;

if(i*100+j*10+k==i*i*i+j*j*j+k*k*k) printf(\"n=%d\\n\ } } 6.7

#define M 1000 main()

{int k0,k1,k2,k3,k4,k5,k6,k7,k8,k9; int i,j,n,s; for(j=2;j<=M;j++) {n=0; s=j;

for(i=1;iswitch(n)

{case 1:k0=i;break; case 2:k1=i;break;

case 3:k2=i;break; case 4:k3=i;break; case 5:k4=i;break; case 6:k5=i;break; case 7:k6=i;break; case 8:k7=i;break; case 9:k8=i;break; case 10:k9=i;break; } } } if(s==0)

{printf(\"j=%d\\n\

if(n>1)printf(\"%d,%d\ if(n>2)printf(\ if(n>3)printf(\ if(n>4)printf(\ if(n>5)printf(\ if(n>6)printf(\ if(n>7)printf(\ if(n>8)printf(\ if(n>9)printf(\ } } }

main()

{static int k[10]; int i,j,n,s;

for(j=2;j<=1000;j++) {n=-1; s=j;

for(i=1;i{printf(\"j=%d\\n\ for(i=0;i} } } 6.8 main()

{int n,t,number=20; float a=2;b=1;s=0;

for(n=1;n<=number;n++) {s=s+a/b; t=a,a=a+b,b=t; }

printf(\"s=%9.6f\\n\} 6.9

main()

{float sn=100.0,hn=sn/2; int n;

for(n=2;n<=10;n++) {sn=sn+2*hn; hn=hn/2; }

printf(\"sn=%f\\n\printf(\"hn=%f\\n\}

6.10 main()

{int day,x1,x2; day=9; x2=1;

while(day>0)

{x1=(x2+1)*2; x2=x1; day--; }

printf(\"x1=%d\\n\} 6.11

#include\"math.h\" main()

{float a,xn0,xn1;

scanf(\"%f\xn0=a/2;

xn1=(xn0+a/xn0)/2; do

{xn0=xn1;

xn1=(xn0+a/xn0)/2; }

while(fabs(xn0-xn1)>=1e-5);

printf(\"a=%5.2f\\n,xn1=%8.2f\\n\} 6.12

#include\"math.h\" main() {float x,x0,f,f1; x=1.5;

do

{x0=x;

f=((2*x0-4)*x0+3)*x0-6; f1=(6*x0-8)*x0+3; x=x0-f/f1;

}

while(fabs(x-x0)>=1e-5); printf(\"x=%6.2f\\n\} 6.13

#include\"math.h\" main()

{float x0,x1,x2,fx0,fx1,fx2; do

{scanf(\"%f,%f\ fx1=x1*((2*x1-4)*x1+3)-6; fx2=x2*((2*x2-4)*x2+3)-6; }

while(fx1*fx2>0); do

{x0=(x1+x2)/2;

fx0=x0*((2*x0-4)*x0+3)-6; if((fx0*fx1)<0) {x2=x0; fx2=fx0; } else

{x1=x0; fx1=fx0; } }

while(fabs(fx0)>=1e-5); printf(\"x0=%6.2f\\n\} 6.14 main()

{int i,j,k;

for(i=0;i<=3;i++) {for(j=0;j<=2-i;j++) printf(\" \"); for(k=0;k<=2*i;k++) printf(\"*\"); printf(\"\\n\"); }

for(i=0;i<=2;i++) {for(j=0;j<=i;j++) printf(\" \");

for(k=0;k<=4-2*i;k++) printf(\"*\"); printf(\"\\n\"); } }

6.15 main() {char i,j,k;

for(i='x';i<='z';i++) for(j='x';j<='z';j++) {if(i!=j)

for(k='x';k<='z';k++)

{if(i!=k&&j!=k)

{if(i!='x'&&k!='x'&&k!='z')

printf(\"\\na--%c\b--%c\c--%c\\n\ } } } }

第七章 数组 7.1

#include #define N 101 main()

{ int i,j,line,a[N];

for (i=2;ifor (i=2,line=0;i{ printf(\"%5d\ line++; } if(line==10) { printf(\"\\n\"); line=0; } } }

7.2

#define N 10 main()

{int i,j,min,temp,a[N]; for(i=0;iscanf(\"%d\for(i=0;ifor(j=i+1;ja[j])min=j; temp=a[i]; a[i]=a[min]; a[min]=temp; }

for(i=0;i{float a[3][3],sum; int i,j;

for(i=0;i<3;i++)

for(j=0;j<3;j++) {scanf(\"%f\ a[i][j]=sum; }

for(i=0;i<3;i++) sum=sum+a[i][i]; printf(\"sum=%f\} 7.4

main()

{int a[11]={1,4,6,9,13,16,19,28,40,100}; int temp1,temp2,number, end,i,j; scanf(\"%d\end=a[9];

if(number>end) a[10]=number; else

{for(i=0;i<10;i++) {if(a[i]>number) {temp1=a[i]; a[i]=number; for(j=i+1;j<11;j++) {temp2=a[j]; a[j]=temp1; temp1=temp2; } break; } } }

for(i=0;i<11;i++)

printf(\"%6d\}

7.5

#define N 5 main()

{int a[N]={8,6,5,4,1},i,temp; for(i=0;ifor(i=0;iprintf(\"%4d\} 7.6

#define N 11 main() {int i,j,a[N][N]; for(i=1;ifor(i=3;ifor(j=2;ja[i][j]=a[i-1][j-1]+a[i-1][j]; for(i=1;i{for(j=1;j<=i;j++) printf(\"%6d\ printf(\"\\n\"); } }

7.7 main()

{int a[16][16],i,j,k,p,m,n; p=1;

while(p==1)

{scanf(\"%d\

if((n!=0)&&(n<=15)&&(n%2!=0))p=0; }

for(i=1;i<=n;i++) for(j=1;j<=n;j++) a[i][j]=0; j=n/2+1; a[1][j]=1;

for(k=2;k<=n*n;k++) {i=i-1; j=j+1;

if((i<1)&&(j>n)) {i=i+2; j=j-1; }

else

{if(i<1)i=n; if(j>n)j=1;

}

if(a[i][j]==0)a[i][j]=k; else

{i=i+2; j=j-1; a[i][j]=k; } }

for(i=1;i<=n;i++) {for(j=1;j<=n;j++) printf(\"%3d\ printf(\"\\n\"); } } 7.8

#define N 10 #define M 10 main()

{int i,j,k,m,n,flag1,flag2,a[N][M],max,maxi,maxj; scanf(\"%d,%d\for(i=0;iscanf(\"%d\flag2=0; for(i=0;ifor(k=0,flag1=1;ka[k][maxj])flag1=0;

if(flag1)

{ printf(\"\\na[%d][%d]=%d\\n\ flag2=1; } }

if(!flag2) printf(\"NOT\"); }

7.9

#include

#define N 15

main()

{int i,j,number,top,bott,min,loca,a[N],flag; char c;

for(i=0;i<=N;i++) scanf(\"%d\flag=1;

while(flag)

{scanf(\"%d\ loca=0; top=0; bott=N-1;

if((numbera[N-1])) loca=-1;

while((loca==0)&&(top<=bott)) {min=(bott+top)/2;

if(number==a[min]) {loca=min;

printf(\"number=%d,loca=%d\\n\ }

else if(numbertop=min+1; }

if(loca==0||loca==-1)

printf(\"%d not in table\\n\ printf(\"continue Y/N or y/n\\n\"); c=getchar();

if(c=='N'||c=='n')flag=0; } } 7.10

main()

{int i,j,uppn,lown,dign,span,othn; char text[3][80];

uppn=lown=dign=span=othn=0; for(i=0;i<3;i++) {gets(text[i]);

for(j=0;j<80&&text[i][j]!='\\0';j++) {if(text[i][j]>='A'&&text[i][j]<='Z') uppn++;

else if(text[i][j]>='a'&&text[i][j]<='z')

lown++;

else if(text[i][j]>='0'&&text[i][j]<='9') dign++;

else if(text[i][j]==' ') span++; else othn++; } }

for(i=0;i<3;i++)

printf(\"%s\\n\printf(\"uppn=%d\\n\printf(\"lown=%d\\n\printf(\"dign=%d\\n\printf(\"span=%d\\n\printf(\"othn=%d\\n\} 7.11 main()

{static char a[5]={'*','*','*','*','*'}; int i,j,k;

char space=' '; for(i=0;i<=5;i++) {printf(\"\\n\");

for(j=1;j<=3*i;j++) printf(\"%1c\ for(k=0;k<=5;k++) printf(\"%3c\ } }

7.12

#include main() {int i,n;

char ch[80],tran[80]; gets(ch); i=0;

while(ch[i]!='\\0')

{if((ch[i]>='A')&&(ch[i]<='Z')) tran[i]=26+-ch[i]+1+; else if((ch[i]>='a')&&(ch[i]<='z')) tran[i]=26+96-ch[i]+1+96;

else

tran[i]=ch[i]; i++; } n=i;

for(i=0;imain()

{char s1[80],s2[40]; int i=0,j=0; scanf(\"%s\scanf(\"%s\

while(s1[i]!='\\0')i++;

while(s2[j]!='\\0')s1[i++]=s2[j++]; s1[i]='\\0';

printf(\"s=%s\\n\}

7.14

#include main() {int i,resu;

char s1[100],s2[100]; gets(s1);

gets(s2); i=0;

while((s1[i]==s2[i])&&(s1[i]!='\\0'))i++; if(s1[i]=='\\0'&&s2[i]=='\\0')resu=0; else

resu=s1[i]-s2[i];

printf(\"s1=%s,s2=%s,resu=%d\\n\} 7.15

#include\"stdio.h\" main()

{char from[80],to[80];; int i;

scanf(\"%s\

for(i=0;i<=strlen(from);i++) to[i]=from[i];

printf(\"%s\\n\}

第八章 8.1 hcf(u,v) int u,v;

{int a,b,t,r;

if(u>v){t=u;u=v;v=t;} a=u;b=v;

while((r=b%a)!=0) {b=a;a=r;} return(a); } lcd(u,v,h) int u,v,h; {return(u*v/h);} main() {int u,v,h,l;

scanf(\"%d,%d\h=hcf(u,v);

printf(\"H.C.F=%d\\n\l=lcd(u,v,h);

printf(\"L.C.D=%d\\n\} 8.2

#include\"math.h\" float x1,x2,disc,p,q; greater_than_zero(a,b) float a,b;

{x1=(-b+sqrt(disc))/(2*a); x2=(-b-sqrt(disc))/(2*a); }

equal_to_zero(a,b) flaot a,b;

{x1=x2=-b/(2*a);} smaller_than_zero(a,b) float a,b; {p=-b/(2*a); q=sqrt(-disc)/(2*a); }

main()

{float a,b,c;

scanf(\"%f,%f,%f\

disc=b*b-4*a*c; if(fabs(disc)<=1e-5) {equal_to_zero(a,b);

printf(\"x1=%5.2f\x2=%5.2f\\n\ } else if(disc>0)

{greater_than_zero(a,b);

printf(\"x1=%5.2f\x2=%5.2f\\n\ }

else

{smaller_than_zero(a,b);

printf(\"x1=%5.2f+%5.2fi\x2=%5.2f-%5.2fi\\n\ } }

8.3 main()

{int number;

scanf(\"%d\if(prime(number)) printf(\"yes\"); else

printf(\"no\"); }

int prime(number) int number;

{int flag=1,n;

for(n=2;n8.4

#define N 3 int array[N][N]; convert(array) int array[3][3]; {int i,j,t; for(i=0;ifor(j=i+1;jarray[i][j]=array[j][i];

array[j][i]=t; } }

main() {int i,j; for(i=0;iscanf(\"%d\convert(array); for(i=0;ifor(j=0;jprintf(\"%5d\ } }

8.5 main()

{char str[100]; scanf(\"%s\inverse(str); printf(\"%s\\n\}

inverse(str) char str[]; {char t; int i,j;

for(i=0,j=strlen(str);istr[i]=str[j-1]; str[j-1]=t; } }

8.6

char concate(str1,str2,str) char str1[],str2[],str[]; {int i,j;

for(i=0;str1[i]!='\\0';i++) str[i]=str1[i]; for(j=0;str2[j]!='\\0';j++) str[i+j]=str2[j]; str[i+j]='\\0'; }

main()

{char s1[100],s2[100],s[100]; scanf(\"%s\scanf(\"%s\concate(s1,s2,s); printf(\"\\ns=%s\} 8.7 main()

{char str[80],c[80]; void cpy(); gets(str); cpy(str,c); printf(\"\\n%s\\n\}

void cpy(s,c) char s[],c[]; {int i,j;

for(i=0,j=0;s[i]!='\\0';i++)

if(s[i]=='a'||s[i]=='A'||s[i]=='e'||s[i]=='E'||s[i]=='i'|| s[i]=='I'||s[i]=='o'||s[i]=='O'||s[i]=='u'||s[i]=='U') {c[j]=s[i];j++;} c[j]='\\0'; } 8.8

main()

{char str[80]; scanf(\"%s\insert(str); } insert(str) char str[];

{int i;

for(i=strlen(str);i>0;i--) {str[i*2]=str[i]; str[i*2-1]=' '; }

printf(\"%s\\n\}

8.9

int alph,digit,space,others;

main()

{char text[80]; gets(text);

alph=0,digit=0,space=0,others=0; count(text);

printf(\"\\nalph=%d,digit=%d,space=%d,others=%d\\n\} count(str) char str[]; {int i;

for(i=0;str[i]!='\\0';i++)

if((str[i]>='a'&&str[i]<='z')||(str[i]>='A'&&str[i]<='Z')) alph++;

else if(str[i]>='0'&&str[i]<='9') digit++;

else if(strcmp(str[i],' ')==0) space++; else

others++; }

8.10

int alph(c) char c;

{if((c>='a'&&c<='z')||(c>='A'&&c<='Z')) return(1); else

return(0); }

int longest(string)

char string[];

{int len=0,i,length=0,flag=1,place,point; for(i=0;i<=strlen(string);i++) if(alph(string[i])) if(flag) {point=i; flag=0; } else len++; else

{flag=1;

if(len>length) {length=len;

place=point; len=0; } } return(place); } main() {int i;

char line[100]; gets(line);

for(i=longest(line);alph(line[i]);i++) printf(\"%c\printf(\"\\n\"); } 8.11 #define N 10 char str[N]; main() {int i,flag;

for(flag=1;flag==1;) {scanf(\"%s\ if(strlen(str)>N)

printf(\"input error\"); else flag=0; }

sort(str);

for(i=0;iprintf(\"%c\}

sort(str) char str[N]; {int i,j; char t;

for(j=1;jfor(i=0;(istr[i+1]) {t=str[i]; str[i]=str[i+1]; str[i+1]=t; } }

8.12

#include float solut(a,b,c,d) float a,b,c,d;

{float x=1,x0,f,f1; do {x0=x;

f=((a*x0+b)*x0+c)*x0+d; f1=(3*a*x0+2*b)*x0+c; x=x0-f/f1;

}

while(fabs(x-x0)>=1e-5); return(x); }

main()

{float a,b,c,d;

scanf(\"%f,%f,%f,%f\printf(\"x=%10.7f\\n\} 8.13

main() {int x,n; float p();

scanf(\"%d,%d\

printf(\"P%d(%d)=%10.2f\\n\}

float p(tn,tx) int tn,tx; {if(tn==0) return(1); else if(tn==1) return(tx); else

return(((2*tn-1)*tx*p((tn-1),tx)-(tn-1)*p((tn-2),tx))/tn); }

8.14

#define N 10 #define M 5 float score[N][M]; float a_stu[N],a_cor[M]; main() {int i,j,r,c;

float h; float s_diff(); float highest(); r=0; c=1; input_stu(); avr_stu();

avr_cor();

printf(\"\\n number class 1 2 3 4 5 avr\"); for(i=0;i{printf(\"\\nNO%2d\ for(j=0;jprintf(\"%8.2f\ printf(\"%8.2f\ }

printf(\"\\nclassavr\"); for(j=0;jprintf(\"%8.2f\h=highest(&r,&c);

printf(\"\\n\\n%8.2f %d %d\\n\printf(\"\\n %8.2f\\n\}

input_stu() {int i,j; float x;

for(i=0;i{for(j=0;jfor(i=0;ifor(j=0;jfloat highest(r,c) int *r,*c; {float high; int i,j;

high=score[0][0]; for(i=0;ihigh) {high=score[i][j]; *r=i+1; *c=j+1; } return(high); }

float s_diff()

{int i,j;

float sumx=0.0,sumxn=0.0; for(i=0;i{sumx+=a_stu[i]*a_stu[i]; sumxn+=a_stu[i]; }

return(sumx/N-(sumxn/N)*(sumxn/N)); }

8.15

#include #define N 10

void input_e(num,name) int num[];

char name[N][8]; {int i;

for(i=0;i{scanf(\"%d\ gets(name[i]); }

}

void sort(num,name) int num[];

char name[N][8]; {int i,j,min,temp1; char temp2[8]; for(i=0;iif(num[min]>num[j])min=j; temp1=num[i]; num[i]=num[min]; num[min]=temp1; strcpy(temp2,name[i]); strcpy(name[i],name[min]); strcpy(name[min],temp2); }

for(i=0;iprintf(\"\\n%5d%10s\}

void search(n,num,name) int n,num[]; char name[N][8]; {int top,bott,min,loca; loca=0; top=0; bott=N-1;

if((nnum[N-1])) loca=-1;

while((loca==0)&&(top<=bott)) {min=(bott+top)/2; if(n==num[min]) {loca=min;

printf(\"number=%d,name=%s\\n\ }

else if(ntop=min+1; }

if(loca==0||loca==-1)

printf(\"number=%d is not in table\\n\} main()

{int num[N],number,flag,c,n; char name[N][8]; input_e(num,name);

sort(num,name);

for(flag=1;flag;)

{scanf(\"%d\ search(number,num,name); printf(\"continue?Y/N!\"); c=getchar(); if(c=='N'||c=='n') flag=0; } } 8.16

#include #define MAX 1000 main()

{int c,i,flag,flag1; char t[MAX]; i=0; flag=0; flag1=1;

while((c=getchar())!='\\0'&&i{if(c>='0'&&c<='9'||c>='A'&&c<='F'||c>='a'&&c<='f') {flag=1; t[i++]=c; } else if(flag) {t[i]='\\0';

printf(\"\\nnumber=%d\\n\ printf(\"continue?\"); c=getchar(); if(c=='n'||c=='N') flag1=0; else

{flag=0; i=0; } } } } htoi(s) char s[];

{int i,n; n=0;

for(i=0;s[i]!='\\0';i++)

{if(s[i]>='0'&&s[i]<='9') n=n*16+s[i]-'0'; if(s[i]>='a'&&s[i]<='f') n=n*16+s[i]-'a'+10; if(s[i]>='A'&&s[i]<='F') n=n*16+s[i]-'A'+10; } return(n); }

8.17

#include void convert(n) int n; {int i;

if((i=n/10)!=0) convert(i);

putchar(n%10+'0'); } main() {int number;

scanf(\"%d\if(number<0) {putchar('-');

number=-number; }

convert(number); } 8.18

main()

{int year,month,day;

int days;

scanf(\"\\n%d,%d,%d\days=sum_day(month,day); if(leap(year)&&(month>=3)) days+=1;

printf(\"days=%d\\n\}

static int day_tab[13]={0,31,28,31,30,31,30,31,31,30,31,30,31} int sum_day(month,day) int month,day; {int i;

for(i=1;iday+=day_tab[i]; return(day); }

int leap(year) int year; {int leap;

leap=year%4==0&&year%100!=0||year%400==0; return(leap); }

第九章 编译预处理 9.1

#define SWAP(a,b) t=b;b=a;a=t main()

{int a,b,t;

scanf(\"%d,%d\SWAP(a,b);

printf(\"a=%d\b=%d\\n\} 9.2

#define SURPLUS(a,b) ((a)%(b)) main() {int a,b;

scanf(\"%d,%d\printf(\"%d\}

9.3

#include\"math.h\"

#define S(a,b,c) ((a+b+c)/2)

#define AREA(a,b,c) (sqrt(S(a,b,c)*(S(a,b,c)-a)*(S(a,b,c)-b)*(S(a,b,c)-c))) main()

{float a,b,c;

scanf(\"%f,%f,%f\if(a+b>c&&b+c>a&&a+c>b)

printf(\"area=%8.2f\\n\else

printf(\"input error\"); }

9.4

#define LEAP(y) (y%4==0)&&(y%100!=0)||(y%400==0) main()

{int year;

scanf(\"%d\if(LEAP(year)) printf(\"yes\"); else

printf(\"no\"); } 8.5

printf(\"value=%format\\

printf(\"value=%format\\

printf(\"value=%format\\输出结果：

value=5.000000ormat value=5.000000ormat value=3.000000ormat value=8.000000ormat

9.6

#define PR printf #define NL \"\\n\" #define Fs \"%f\" #define F \"%6.2f\"

#define F1 F NL

#define F2 F \"\\" F NL

#define F3 F \"\\" F \"\\" F NL main() {float a,b,c; scanf(Fs,&a); scanf(Fs,&b); scanf(Fs,&c); PR(NL); PR(F1,a); PR(F1,b); PR(F1,c); PR(NL); PR(F2,a,b); PR(F1,c); PR(NL); PR(F3,a,b,c); }

9.7

/*format.h文件*/

#define DIGIT(d) printf(\"%d\\n\#define FLOAT(f) printf(\"%8.2f\\n\

#define STRING(s) printf(\"%s\\n\/*用户文件*/ #include\"format.h\" main() {int d,num; float f; char s[80]; scanf(\"%d\switch(num)

{case 1:scanf(\"%d\ DIGIT(d); break; case 2:scanf(\"%f\ FLOAT(f); break;

case 3:scanf(\"%s\ STRING(s); break;

default:printf(\"error\"); } } 9.8 main() {int a,b,c;

scanf(\"%d,%d,%d\printf(\"max=%d\\n\}

max(a,b,c) int a,b,c; {int t;

t=x>y?x:y; return(t>z?t:z); }

#define MAX(a,b) ((a)>(b)?(a):(b)) main()

{int a,b,c;

scanf(\"%d,%d,%d\printf(\"max=%d\\n\}

9.10

#include\"stdio.h\"

#define MAX 80 #define CHANGE 1 main()

{char str[MAX]; int i;

scanf(\"%s\#if(CHANGE)

{for(i=0;iif(str[i]>='a'&&str[i]<'z'||str[i]>='A'&&str[i]<'Z') str[i]++;

else if(str[i]=='z'||str[i]=='Z') str[i]-=25; } } #endif

printf(\"\\n%s\\n\}

第十章 指针 10.1 main()

{int n1,n2,n3;

int *p1,*p2,*p3;

scanf(\"%d,%d,%d\p1=&n1; p2=&n2; p3=&n3;

if(n1>n2)swap(p1,p2); if(n1>n3)swap(p1,p3); if(n2>n3)swap(p2,p3);

printf(\"%d,%d,%d\\n\}

swap(p1,p2) int *p1,*p2;

{int p;

p=*p1;*p1=*p2;*p2=p; }

10.2 main()

{char *str1[20],*str2[20],*str3[20];

char swap();

scanf(\"%s\scanf(\"%s\scanf(\"%s\

if(strcmp(str1,str2)>0)swap(str1,str2); if(strcmp(str1,str3)>0)swap(str1,str3); if(strcmp(str2,str3)>0)swap(str2,str3); printf(\"%s\\n%s\\n%s\\n\}

char swap(p1,p2) char *p1,*p2; {char *p[20]; strcpy(p,p1); strcpy(p1,p2); strcpy(p2,p); } 10.3 main()

{int number[10]; input(number);

max_min_value(number); output(number); }

input(number) int number[10]; {int i;

for(i=0;i<10;i++)

scanf(\"%d\}

max_min_value(number) int number[10]; {int *max,*min; int *p,*end; end=number+10; max=min=number;

for(p=number+1;p*max)max=p; else if(*p<*min)min=p; *p=number[0]; number[0]=*min; *min=*p;

*p=number[9]; number[9]=*max;

*max=*p; return; }

output(number) int number[10]; {int *p;

for(p=number;pmain()

{int number[20],n,m,i; scanf(\"%d\scanf(\"%d\

for(i=0;iscanf(\"%d\move(number,n,m); for(i=0;iprintf(\"%8d\}

move(array,n,m) int array[20],n,m; {int *p,end;

end=*(array+n-1);

for(p=array+n-1;p>array;p--) *p=*(p-1); *array=end; m--;

if(m>0)move(array,n,m); } 10.5

#define nmax 50 main()

{int i,k,m,n,num[nmax],*p; scanf(\"%d\p=num; for(i=0;i{if(*(p+i)!=0)k++;

if(k==3) {*(p+i)=0; k=0; m++; } i++; if(i==n)i=0; }

while(*p==0)p++; printf(\"%d\} 10.6 main() {int len;

char *str[20];

scanf(\"%s\len=length(str);

printf(\"\\nlen=%d\\n\} length(p) char *p; {int n=0;

while(*p!='\\0') {n++;p++;} return(n); } 10.7 main()

{int m;

char *str1[20],*str2[20]; scanf(\"%s\scanf(\"%d\if(strlen(str1){copystr(str1,str2,m); printf(\"%s\ } }

copystr(p1,p2,m) char *p1,*p2; int m;

{int n=0; while(n#include\"stdio.h\" main()

{int cle=0,sle=0,di=0,wsp=0,ot=0,i; char *p,s[20];

for(i=0;i<20;i++)s[i]=0; i=0;

while((s[i]=getchar())!='\\n')i++; p=s;

while(*p!='\\n')

{if(*p>='a'&&*p<='z') ++sle;

else if(*p>='A'&&*p<='Z') ++cle; else if(*p==' ') ++wsp;

else if(*p>='0'&&*p<='9') ++di; else ++ot; p++;

}

printf(\"sle=%d,cle=%d,wsp=%d,di=%d,ot=%d\\n\} 10.9

main()

{int a[3][3],*p,i; for(i=0;i<3;i++)

scanf(\"%d,%d,%d\p=a; move(p);

for(i=0;i<3;i++)

printf(\"%d %d %d\\n\}

move(pointer) int *pointer; {int i,j,t; for(i=0;i<2;i++) for(j=i+1;j<3;j++)

{t=*(pointer+3*i+j);

*(pointer+3*i+j)=*(pointer+3*j+i); *(pointer+3*j+i)=t; } }

10.10

main()

{int a[5][5],*p,i,j; for(i=0;i<5;i++) for(j=0;j<5;j++)

scanf(\"%d\p=a; change(p);

for(i=0;i<5;i++) {printf(\"\\n\"); for(j=0;j<5;j++)

printf(\"%8d\ } }

change(p) int *p;

{int i,j,change; int *pmax,*pmin; pmax=p; pmin=p;

for(i=0;i<5;i++)

for(j=0;j<5;j++)

{if(*pmax<*(p+5*i+j))pmax=p+5*i+j; if(*pmin>*(p+5*i+j))pmin=p+5*i+j; }

change=*(p+12); *(p+12)=*pmax; *pmax=change; change=*p; *p=*pmin; *pmin=change;

pmin=p+1;

for(i=0;i<5;i++) for(j=0;j<5;j++)

if(((p+5*i+j)!=p)&&(*pmin>*(p+5*i+j)))pmin=p+5*i+j; change=*(p+4); *(p+4)=*pmin; *pmin=change; pmin=p+1;

for(i=0;i<5;i++) for(j=0;j<5;j++)

if(((p+5*i+j)!=(p+4))&&((p+5*i+j)!=p)&&(*pmin>*(p+5*i+j))) pmin=p+5*i+j; change=*(p+20); *(p+20)=*pmin; *pmin=change; pmin=p+1;

for(i=0;i<5;i++) for(j=0;j<5;j++)

if(((p+5*i+j)!=p)&&((p+5*i+j)!=(p+4))&&((p+5*i+j)!=(p+20)) &&(*pmin>*(p+5*i+j)))pmin=p+5*i+j; change=*(p+24); *(p+24)=*pmin; *pmin=change; } 10.11 main()

{int i;

char *p,str[10][10]; for(i=0;i<10;i++) scanf(\"%s\p=str;

sort(p);

for(i=0;i<10;i++) printf(\"%s\\n\} sort(p) char *p; {int i,j;

char s[10],*smax,*smin; for(i=0;i<10;i++) {smax=p+10*i;

for(j=i+1;j<10;j++) {smin=p+10*j;

if(strcmp(smax,smin)>0) {strcpy(s,smin); strcpy(smin,smax); strcpy(smax,s); } } } } 10.12

#define MAX 20 main()

{int i;

char *pstr[10],str[10][MAX]; for(i=0;i<10;i++) pstr[i]=str[i]; for(i=0;i<10;i++)

scanf(\"%s\sort(pstr); for(i=0;i<10;i++) printf(\"%s\\n\}

sort(pstr)

char *pstr[10]; {int i,j;

char *p;

for(i=0;i<10;i++)

{for(j=i+1;j<10;j++)

{if(strcmp(*(pstr+i),*(pstr+j))>0) {p=*(pstr+i); *(pstr+i)=*(pstr+j); *(pstr+j)=p; } } } }

10.13

#include\"math.h\" main() {int n=20;

float a,b,a1,b1,a2,b2,c,(*p)(),jiff(); scanf(\"%f,%f\scanf(\"%f,%f\

scanf(\"%f,%f\p=sin;

c=jiff(a,b,n,p);

printf(\"sin=%f\\n\p=cos;

c=jiff(a1,b1,n,p); printf(\"cos=%f\\n\p=exp;

c=jiff(a2,b2,n,p); printf(\"exp=%f\\n\}

float jiff(a,b,n,p) float a,b,(*p)(); int n;

{int i;

float x,f,h,area; h=(b-a)/n; x=a; area=0;

for(i=1;i<=n;i++) {x=x+h;

area=area+(*p)(x)*h; }

return(area); }

10.14

main()

{int i,n,num[20]; char *p; scanf(\"%d\for(i=0;ifor(i=0;isort(p,m) char *p; int m;

{int i;

char change,*p1,*p2; for(i=0;i{p1=p+i; p2=p+(m-1-i); change=*p1; *p1=*p2; *p2=change; } }

10.15 main()

{int i,j,*pnum,num[4];

float score[4][5],aver[4],*psco,*pave; char course[5][10],*pcou; pcou=course[0];

for(i=0;i<5;i++)

scanf(\"%s\printf(\"number\"); for(i=0;i<5;i++)

printf(\printf(\"\\n\"); psco=score;

pnum=num; for(i=0;i<4;i++)

{scanf(\"%d\ for(j=0;j<5;j++)

scanf(\ }

pave=aver; printf(\"\\n\");

avsco(psco,pave); avcour1(pcou,psco); printf(\"\\n\");

fali2(pcou,pnum,psco,pave); printf(\"\\n\");

good(pcou,pnum,psco,pave); }

avsco(psco,pave) float *psco,*pave; {int i,j;

float sum,average; for(i=0;i<4;i++)

{sum=0;

for(j=0;j<5;j+)

sum+=(*(psco+5*i+j));

average=sum/5; *(pave+i)=average; } }

avcour1(pcou,psco) char *pcou; float *psco; {int i;

float sum,average1; sum=0;

for(i=0;i<4;i++)

sum+=(*(psco+5*i))

average1=sum/4;

printf(\"%s %5.2f\\n\}

fali2(pcou,pnum,psco,pave) char *pcou; int *pnum;

float *psco,*pave; {int i,j,k,label; printf(\"\\nnumber\\n\"); for(i=0;i<5;i++)

printf(\"%-8s\printf(\"\\naverage\\n\"); for(i=0;i<4;i++) {label=0;

for(j=0;j<5;j++)

if(*(psco+5*i+j)<60.0)label++; if(label>=2)

{printf(\"%-8d\ for(k=0;k<5;k++)

printf(\"%-8.2f\ printf(\"%-8.2f\ } } }

good(pcou,pnum,psco,pave) char *pcou; int *pnum; float *psco,*pave; {int i,j,k,label;

printf(\"number\"); for(i=0;i<5;i++)

printf(\"%-8s\

printf(\"average\");

for(i=0;i<4;i++) {label=0;

for(j=0;j<5;j++)

if(*(psco+5*i+j)>=85.0)label++; if((label>=5)||(*(pave+i)>=90)) {printf(\"%-8d\ for(k=0;k<5;k++)

printf(\"%-8.2f\ printf(\"%-8.2f\ } } }

10.16

#include\"stdio.h\"

main()

{char str[50],*pstr;

int i,j,k,m,e10,digit,ndigit,a[10],*pa; gets(str); pstr=str;

pa=a; ndigit=0; i=j=0;

while(*(pstr+i)!='\\0')

{if((*(pstr+i)>='0')&&(*(pstr+i)<='9')) j++;

else

{if(j>0)

{digit=*(pstr+i-1)-48; k=1;

while(k{e10=1;

for(m=1;m<=k;m++) e10=e10*10;

digit+=(*(pstr+i-1-k)-48)*e10; k++; }

*pa=digit; ndigit++; pa++; j=0; } }

i++;

} if(j>0)

{digit=*(pstr+i-1)-48; k=1; while(kfor(m=1;m<=k;m++) e10=e10*10;

digit+=(*(pstr+i-1-k)-48)*e10; k++; } *pa=digit; ndigit++; j=0; }

printf(\"ndigit=%d\\n\j=0; pa=a;

for(j=0;j10.17 main()

{int m;

char str1[20],str2[20],*p1,*p2; scanf(\"%s\scanf(\"%s\p1=str1; p2=str2;

m=strcmp(p1,p2); printf(\"%d\\n\}

strcmp(p1,p2) char *p1,*p2; {int i=0;

while(*(p1+i)==*(p2+i))

if(*(p+i++)=='\\0')return(0); return(*(p1+i)-*(p2+i)); }

10.18 main()

{static char *mname[13]={\"illeagl\ \"April\ \"November\int n;

scanf(\"%d\if((n>=1)&&(n<=12))

printf(\"%s\\n\else

printf(\"error\"); }

10.20 main() {int i;

char **p,*pstr[5],str[5][10]; for(i=0;i<5;i++) pstr[i]=str[i]; for(i=0;i<5;i++)

scanf(\"%s\p=pstr; sort(p);

for(i=0;i<5;i++)

printf(\"%s\\n\}

sort(p) char **P; {int i,j;

char *pchange; for(i=0;i<5;i++)

{for(j=i+1;j<5;j++)

{if(strcmp(*(p+i),*(p+j))>0) {pchange=*(p+i); *(p+i)=*(p+j); *(p+j)=pchange; } } } } 10.21 main()

{int i,n,digit[20],**p,*pstr[20]; scanf(\"%d\for(i=0;ipstr[i]=&digit[i]; for(i=0;iscanf(\"%d\p=pstr; sort(p,n); for(i=0;iprintf(\"%d \}

sort(p,n) int **p,n; {int i,j,*pchange; for(i=0;i{for(j=i+1;j{if(**(p+i)>**(p+j)) {pchange=*(p+i); *(p+i)=*(p+j); *(p+j)=pchange; } } } }

第十一章 结构体与共用体 11.1 struct {int year; int month; int day; }date; main()

{int days;

scanf(\"%d,%d,%d\switch(date.month)

{case 1:days=date.day;break; case 2:days=date.day+31;break; case 3:days=date.day+59;break; case 4:days=date.day+90;break; case 5:days=date.day+120;break; case 6:days=date.day+151;break; case 7:days=date.day+181;break; case 8:days=date.day+212;break; case 9:days=date.day+243;break;

case 10:days=date.day+273;break;

case 11:days=date.day+304;break; case 12:days=date.day+334;break; }

if((date.year%4==0&&date.year%100!=0||date.year%400==0) &&date.month>=3) days+=1;

printf(\"days=%d\\n\} 11.2 struct dt {int year; int month; int day; }date;

main() {

scanf(\"%d,%d,%d\printf(\"\\n%d\\n\}

days(year,month,day) int year,month,day; {int daysum=0,i;

static int daytab[13]={0,31,28,31,30,31,30,31,31,30,31,30,31} for(i=1;idaysum+=day;

if((year%4==0&&year%100!=0||year%400==0)&&month>=3) daysum+=1; return(daysum); } 11.3 11.4

#define N 5 struct student {char num[6]; char name[8]; int score[4]; }stu[N]; main() {

input(stu);

print(stu); }

input(stu)

struct student stu[]; {int i,j; for(i=0;i{printf(\"\\nscore\\n\");

scanf(\"%d\ } printf(\"\\n\"); }

}

print(stu)

struct student stu[]; {int i,j;

printf(\"\\nnumber name score1 score2 score3 \\n\"); for(i=0;i{printf(\"%8s%10s\ for(j=0;j<3;j++)

printf(\"%7d\ printf(\"\\n\"); } } 11.5

struct student {char num[6]; char name[8]; int score[4]; float avr; }stu[5]; main()

{int i,j,max,maxi,sum; float average; for(i=0;i<5;i++) {printf(\"number\"); scanf(\"%s\ printf(\"name\");

scanf(\"%s\

for(j=0;j<3;j++)

{printf(\"\\nscore\\n\");

scanf(\"%d\ } } average=0; max=0; maxi=0;

for(i=0;i<5;i++) {sum=0;

for(j=0;j<3;j++)

sum+=stu[i].score[j]; stu[i].avr=sum/3.0; average+=stu[i].avr; if(sum>max) {max=sum; maxi=i; } } average/=5;

printf(\"number name score1 score2 score3 average\\n\"); for(i=0;i<5;i++)

{printf(\"%8s%10s\ for(j=0;j<3;j++)

printf(\"%7d\ printf(\"%6.2f\\n\ }

printf(\"average=%5.2f\\n\

printf(\"The best student is %s,sum=%d\\n\}