二级C语言课后编程答案的整理版

3.16main(){ float a,b,c,s,v;printf("input a,b,c:");scanf("%f %f %f:",&a,&b,&c);s=a*b;v=a*b*c;printf("a=%f,b=%f,c=%f\n",a,b,c); printf("s=%f,v=%f\n",s,v);}3.17main(){ int h,m;h=560/60;m=560%60;3.18main(){ int m,n;printf("input m & n:");scanf("%d%d",&m,&n);printf("\n%d,%d\n",m/n,m%n);getch();}3.19main(){ double x,y,z,s;printf("input x,y,z: ");scanf("%lf%lf%lf",&x,&y,&z);s=(x+y+z)/3.0;printf("\nAverage=%6.1lf\n",s);getch();}3.20main(){ int a,b,c,t;printf("Input a,b,c: ");scanf("%d%d%d",&a,&b,&c);t=c;c=b;b=a;a=t;printf("\na,b,c=%d,%d,%d\n",a,b,c); getch();}【4-21】main(){ int a,m;printf("input a: ");scanf("%d",&a);switch(a/10){ case 0:case 1:case 2: m=1 ;break;case 3: m=2 ;break;case 4: m=3 ;break;case 5: m=4 ;break;default: m=5;}printf("a,m=%d, %d",a,m );getch();}【4-22】main(){ int age,y0,m0,d0,y1,m1,d1;printf("\ninput a stedent\' birthday (yy-mm-dd): ");scanf("%d-%d-%d",&y0,&m0,&d0);printf("\ninput today\' date(yy-mm-dd): ");scanf("%d-%d-%d",&y1,&m1,&d1);if ((m1>m0)||(m1==m0)&&(d1>=d0)) age=y1-y0;else age=y1-y0-1;printf("\nThe student\' ageis %d",age);getch();}【4-23】main(){ int m;printf("\ninput a integer: ");scanf("%d",&m);if (m%2==0) printf("\n%d is event.",m);else printf("\n%d is ord.",m);getch();}【4-24】main(){ int a,b,c,max;printf("\ninput a,b,c: ");scanf("%d%d%d",&a,&b,&c);max=a;if (b>max) max=b;if (c>max) max=c;printf("max is %d",max);getch();}【4-25-1】main(){ int x,y;printf("\ninput x: ");scanf("%d",&x);if((x>-5)&&(x<0)) y=x;if (x==0) y=x-1;if ((x>0)&&(x<10)) y=x+1;printf("\nx is %d , y is %d",x,y); getch();}【4-25-2】main(){ int x,y;printf("\ninput x: ");scanf("%d",&x);if((x>-5)&&(x<10)){ if (x<0) y=x;if (x==0) y=x-1;if (x>0) y=x+1;printf("\nx is %d , y is %d",x,y); }else printf("input x iserror ! %c",'\007');getch();}【4-25-3】main(){ int x,y;printf("\ninput x: ");scanf("%d",&x);if ((x>-5)&&(x<0)) y=x;else if (x==0) y=x-1;else if ((x>0)&&(x<10)) y=x+1; printf("\nx is %d , y is %d",x,y); getch();}【4-25-4】main(){ int x,y;printf("\ninput x: ");scanf("%d",&x);switch(x){ case -4:case -3:case -2:case -1: y=x;break;case 0 : y=x-1;break;case 1 :case 2 :case 3 :case 4 :case 5 :case 6 :case 7 :case 8 :case 9 : y=x+1;break;default : printf("Input xerror ! %c",7);}printf("\nx is %d , y is %d",x,y); getch();}【5-17】main(){ int i,s=1,k=-1;for (i=1;i<=50;i++){ s=s+k*(2*i+1);k=-k;}printf("s=%d",s);getch();}【5-18-1】main(){ int i=1;double e=1.0,s=1.0;for(i=1;i<=50;i++){s=s*i;e=e+1/s;}printf("e=%lf",e);getch();}【5-18-2】main(){ int i=1;float e=1.0,s=1.0;while (1/s>=1e-04) /* 8 times */ {s=s*i;i++;e=e+1/s;}printf("e=%10.6f",e);getch();}【5-19】main(){ int y,k=0;for(y=1000;y<=2000;y++){ if (y%4==0&&y%100!=0||y%400==0) {printf("%10d",y);k++;}if (k%3==0) printf("\n");}getch();}【5-20】#include <stdio.h>main(){int i,j,n;printf("Input n (1--10):"); do scanf("%d",&n);while (n<1||n>10);for (i=1;i<=n;i++){for (j=1;j<=40-i;j++)printf(" ");for (j=1;j<=2*i-1;j++)printf("*");printf("\n");}for (i=n+1;i<=2*n-1;i++){ for (j=1;j<=40-2*n+i;j++) printf(" ");for (j=1;j<=4*n-1-2*i;j++) printf("*");printf("\n");}getch();}【6-20】#include <stdio.h>main(){ int k=0; char ch;while((ch=getchar())!=10) { k++;printf("%4c%4d",ch,ch); if(k%3==0) printf("\n"); }getch();}【6-21】#include <stdio.h>main(){ long k=0; char ch;while((ch=getchar())!=EOF) { if (ch>='0'&&ch<='9'){ ch=ch-'0';k=k*10+ch;}}printf("%ld",k);getch();}【6-22】#include <stdio.h>main(){ int flag,k=0; char ch;while((ch=getchar())!=EOF){ if (ch==10) { k++; flag=0; }else flag=1;}if (flag==1) k++;printf("\n The line numberis %d\n",k);getch();}【6-23】#include <stdio.h>main(){ int k=0; char ch;while((ch=getchar())!=10)if (ch>='a'&&ch<='z') k++;printf("\n The lower letter number is %d\n",k);getch();}【6-24】#include <stdio.h>main(){ int i,j,n;printf("Input line number : ");scanf("%d",&n);for(i=1;i<=n;i++){ for (j=1;j<=40-i;j++)printf(" ");for(j=1;j<=2*i-1;j++)printf("%c",64+i);printf("\n");}getch();}【7-15】main(){int a,b;printf("Input a & b:"); scanf("%d%d",&a,&b);printf("\n%d%%%d=%d",a,b,mymod(a,b)); getch();}mymod(int a, int b){int z;z=a%b;return z;}【7-16】float fun(int n){return (1.0/n);}main(){int i,n,k=1;float s=0.0;printf("Input n:");scanf("%d",&n);for(i=1;i<=n;i++){s+=k*fun(i);k=-k;}printf("\ns=%8.6f",s);getch();}【7-17】float f(int m){ float t=1.0;int i;for (i=2;i<=m;i++)t-=1.0/(i*i);return t;}main(){int n;printf("Input n:");scanf("%d",&n);printf("\nt=%8.6f",f(n));getch();}【7-18】#include <math.h>float f(float x){ float z;z=x*x-5*x+4;return z;}main(){float x,y1,y2,y3;printf("Input x: ");scanf("%f",&x);y1=f(2);y2=f(x+15);y3=f(sin(x));printf("y1=%10.4f\n",y1);printf("y2=%10.4f\n",y2);printf("y3=%10.4f\n",y3);printf("\n**** END ****");getch();}【8-17-1】fun(x,y)int *x,*y;{int z1,z2;z1=*x+*y;z2=*x-*y;*x=z1; *y=z2;}main(){int *a,*b,A,B;a=&A,b=&B;printf("input two numbers: ");scanf("%d%d",a,b);printf("a,b=%d,%d\n",*a,*b);printf("before call function:\n"); printf("a=%d b=%d\n",*a,*b);fun(a,b);printf("after call function:\n"); printf("a=%d b=%d\n",*a,*b); getch();}【8-17-2】fun(x,y) float *x,*y;{float z1,z2;z1=*x+*y;z2=*x-*y;*x=z1; *y=z2;}main(){float *a,*b,A,B;a=&A;b=&B;printf("input two real numbers: "); scanf("%f%f",a,b);printf("a,b=%f, %f\n",*a,*b);printf("before call function:\n"); printf("a=%f b=%f\n",*a,*b);fun(a,b);printf("after call function:\n"); printf("a=%f b=%f\n",*a,*b);getch();}【8-18】fun(int *a,int *b,int *c){ int max,min;max=*a;min=*a;if (*b>*a) max=*b;if (*b<*a) min=*b;if (*c>max) max=*c;if (*c<min) min=*c;*a=max;*c=min;}main(){int a,b,c;printf("Input a,b,c: ");scanf("%d%d%d",&a,&b,&c);printf("before call function:\n"); printf("a=%d b=%dc=%d\n",a,b,c);fun(&a,&b,&c);printf("after call function:\n"); printf("max=%d min=%d\n",a,c);getch();}【9-27】#include <ctype.h>main(){ char *s,a[100];int i,k=0,num[10]={0};s=a;printf("Input an number string: "); scanf("%s",s);while(*s!='\0'){ if (isdigit(*s)&&(*s>'0'))num[*s-49]++;if (*s==48) num[9]++;s++;}for (i=0;i<9;i++)printf("%2d-->%3d\n",i+1,num[i]); printf(" 0-->%3d\n",num[9]);printf("***** TOTAL *****\n");for (i=0;i<=9;i++) k+=num[i];printf(" %d ",k);getch();}【9-28】move(int a[10],int n){int i;for (i=n;i<10;i++)a[i-1]=a[i];a[9]=0;}main(){int x[10],i,n;printf("input 10 number:");for(i=0;i<10;i++)scanf("%d",&x[i]);printf("\ninput the N:");scanf("%d",&n);move(x,n);printf("\nAfter move tne member list is :\n");for (i=0;i<10;i++)printf("%d ",x[i]);getch();} 【9-29】main(){int a[100]={0},b[100]={0},i,j;printf("\nInput the number list (end with 32767) :\n ");for(i=0;i<100;i++){scanf("%d",&a[i]);if ( a[i]==32767) break;}i--;odd(a,b,i);printf("\narray B :\n");for (i=0;i<100;i++)if (b[i]!=0) printf("%d ",b[i]); else break;getch();}odd(int a[100],int b[100],int n){ int i,j=0;for(i=0;i<=n;i++)if(a[i]%2!=0) b[j++]=a[i];}【9-30】#include <string.h>sort(char s[],int n){int i,j,p,t;for(j=0;j<(n-1);j++){p=j;for(i=j+1;i<n;i++)if(s[p]<s[i]) p=i;if(p!=j) { t=s[j]; s[j]=s[p];s[p]=t; }}}main(){char *s;int n;printf("\nInput s:");scanf("%s",s);n=strlen(s);sort(s,n);printf("\nthe sorted string is %s\n",s);getch();}【9-31】main(){int a[100],n,*p,i=1;a[0]=-32768; p=a+1;printf("\nInput an number list (end with 32767) :\n");do{scanf("%d",&a[i]);if (a[i]>=a[i-1]) i++;}while(a[i-1]!=32767);printf("\nInput inserted number: "); scanf("%d",&n);p=a;insert(p,n);p=a+1;printf("\nOutput array a:\n");doif (*p!=32767) printf("%d ",*p++); while (*p!=32767);getch();}insert( int *q, int n){ int *k;k=q;while (*q!=32767) q++;*(q+1)=*q;while(q>k){ if (n>*(q-1)) { *q=n; break; }else {q--; *(q+1)=*q; }}}【9-32】main(){int n,a[16]={0},*p;printf("\nInput an number:"); scanf("%d",&n);p=a;change(a,n,p);printf("n=%d\n",n);while(p<=a+15)printf("%d",*p++);}change(x,n,p)int x[16],n,*p;{p=x+15; *p=0;if(n==0) return(0);while(n!=0){*p=n%2;p--;n/=2;}}【9-33】#include <stdio.h>main(){int a[15],*p,i;p=a;frandm(a);printf("\nThe array a is: "); for(i=0;i<15;i++)printf("%d ",*p++);}frandm( a[]);{int k=0,i,x,*q;for (i=0;i<15;i++) a[i]=20; while(k<15){x=rand()%20;for (i=0;i<15;i++)if (a[i]==x ) continue;else a[k++]=x;}}【9-34】#define N 20main(){inta[N][N],x[N]={0},y[N]={0},i,j,m,sum=0 ;printf("\n Input N (<20) :");scanf("%d",&m);printf("\n Input arraya[%d][%d]:\n",m,m);for(i=0;i<m;i++)for(j=0;j<m;j++){ scanf("%d",&a[i][j]);x[i]+=a[i][j]; y[j]+=a[i][j];if (i==j ) sum+=a[i][i];}printf("\n After compute : \n");for (i=0;i<m;i++){ for (j=0;j<m;j++)printf("%5d",a[i][j]);printf("%5d\n",x[i]);}for (i=0;i<m;i++)printf("%5d",y[i]);printf("\n\nSum=%d\n",sum);getch();}【9-35】#define N 20main(){int a[N][N],b[N][N],c[N][N],m,n,i,j; printf("\n Input m,n (<20) :");scanf("%d%d",&m,&n);printf("\n Input arrayA[%d][%d]:\n",m,n);for(i=0;i<m;i++)for(j=0;j<n;j++){ scanf("%d",&a[i][j]);}printf("\n Input arrayB[%d][%d]:\n",m,n);for(i=0;i<m;i++)for(j=0;j<n;j++) { scanf("%d",&b[i][j]);c[i][j]=a[i][j]+b[i][j];}printf("\n After compute array C: \n"); for (i=0;i<m;i++){ for (j=0;j<n;j++)printf("%5d",c[i][j]);printf("\n");}getch();}【9-36】main(){int i,j,k;printf("\n ** A MULTIPLICATION TABLE **\n");printf(" ");for(i=1;i<10;i++)printf("(%3d)",i);printf("\n--------------------------------------------\n");for(i=1;i<10;i++){ for(j=0;j<10;j++)if(j==0) printf("( %d)",i);else printf("%5d",i*j);printf("\n");}printf("\n--------------------------------------------\n");getch();}【9-37】#include "stdio.h"#include "stdlib.h"main(){static int m[5][5]={0},i,j;int k=0;printf("\nBefore :\n");for (i=0;i<5;i++)for(j=0;j<5;j++){ m[i][j]=rand()%100;printf("%4d",m[i][j]);if ((++k)%5==0)printf("\n"); }printf("\nAfter:\n");for (i=0;i<5;i++)for(j=0;j<i;j++){ k=m[i][j]; m[i][j]=m[j][i]; m[j][i]=k; }k=0;for (i=0;i<5;i++)for(j=0;j<5;j++){ printf("%4d",m[i][j]);if ((++k)%5==0)printf("\n"); }printf("\n Program end ! \n");}【9-38】#include "stdio.h"main(){ int m[5][5]={0},i,j;int k=0;printf("\nBefore :\n");for (i=0;i<5;i++)for(j=0;j<5;j++){ m[i][j]=rand()%100;printf("%4d",m[i][j]);if ((++k)%5==0)printf("\n"); }printf("\nAfter:\n");for (i=0;i<5;i++)for(j=0;j<i;j++){ k=m[i][j]; m[i][j]=m[j][i]; m[j][i]=k; }printf("%4d",m[i][j]);if ((++k)%5==0)printf("\n"); }k=0;for (i=0;i<5;i++)for(j=0;j<5;j++) { printf("%4d",m[i][j]);if ((++k)%5==0)printf("\n"); }printf("\n Program end ! \n"); getch();}【10-10】#include <string.h>main(){ char str1[]="string",str2[8],*str3,*str4="string";strcpy(str1,"HELLO1");strcpy(str2,"HELLO2");strcpy(str3,"HELLO3");strcpy(str4,"HELLO4");printf("%s\n%s\n%s\n%s\n",str1,str2,s tr3,str4);getch();}【10-13】main(){char *p[]={"BOOL","OPK","H","SP"}; int i;for(i=3;i>=0;i--,i--)printf("%c",*p[i]);printf("\n");getch();}【10-19】#include <stdio.h>#include <string.h>mygets(s)char *s;{ char ch;ch=getchar();while (ch!=10){*s=ch; s++;ch=getchar();}*s='\0';}myputs(s)char *s;{ int i,n;n=strlen(s);for(i=0;i<n;i++)putchar(*s++);}main(){char *str,s[80];str=s;printf("Input a string:");mygets(str);printf("\nOutput the string:\n"); myputs(str);printf("\n");getch();}【10-20】#include <string.h>main(){ char *str ;str=(char*)malloc(1);printf("Input a string:\n" );gets(str);if (fun(str)) printf("\nThis is back-round-text\n");else printf("\nThis is not back-round-text\n");getch();}fun(char *s){int n,i,j, flag=1;n=strlen(s);for (i=0,j=n-1;i<j;i++,j--)if(*(s+i)!=*(s+j)) flag=0;return(flag);}【10-21】#include <string.h>#include <stdio.h>char deltet(s,n)char *s; int n;{ char ch; if (n>strlen(s)) {printf("\nCANNOT DELETE IT !!! %c",007);return('\0'); }else{ ch=*(s+n);do{ *(s+n)=*(s+n+1); n++; }while(*(s+n-1)!='\0');return(ch);}}main(){char str[80],*p,ch;int n;printf("\nInput a string:\n");p=str+1;gets(p);printf("\nDelete the n'th character: ");scanf("%d",&n);ch=deltet(str,n);printf("\nAfter delete thestring :(ch=%c)\n",ch);for(n=1;n<strlen(str);n++)putchar(*p++);getch();。