C语言程序设计习题集答案

第1～2章C语言概述、算法、数据类型、运算符与表达式一、选择题ACDBB CCDCB D二、填空题1、n=202、a=66,b=E第3章顺序程序设计一、选择题BAAD二、程序阅读1、12 240 122、2,3,2,23、0三、编程1#include <stdio.h>#include <math.h>void main(){int a,b,c;float s,area;scanf("%d,%d,%d",&a,&b,&c);s=(a+b+c)/2.0;area=sqrt(s*(s-a)*(s-b)*(s-c));printf("a=%f,b=%f,c=%f,s=%f,area=%f",a,b,c,s*2,area);}2#include <stdio.h>#include <math.h>void main(){float a,b,c,del,x1,x2;scanf("%f,%f,%f",&a,&b,&c);del=b*b-4*a*c;if (del>=0){x1=(-b+sqrt(del))/(2*a);x2=(-b-sqrt(del))/(2*a);printf("x1=%f,x2=%f",x1,x2);}elseprintf("没有实根");}3#include <stdio.h>void main(){int c,f;printf(“input c:\n”);scanf(“%d”,&c);f=9.0/5.0*c+32;printf("%d的华氏温度是%d",c,f);}3.2 选择结构程序设计一、选择题DBBCD C二、程序阅读1、|a|+|b|=612、PQ3、-14、60~6960Error!5、0,16、a+b+c=15三、编程1#include <stdio.h>void main(){int a,b,c,min;scanf("%d,%d,%d",&a,&b,&c);min=a;if (min>b) min=b;if (min>c) min=c;printf(“%d,”,min);}2#include <stdio.h>void main(){int a;scanf("%d",&a);if(a%3==0 && a%5==0 && a%7==0)printf("yes");elseprintf("no");}3#include <stdio.h>#include <math.h>void main(){float x,y;scanf("%f",&x);if (x<0)y=fabs(x);else if(x>=0 && x<=2)y=sqrt(x+1);else if (x>=2 && x<4)y=pow(x+2,3);elsey=2*x+5;printf("x=%f,y=%f",x,y);}4#include <stdio.h>void main(){float rate,tax,salary;scanf("%f",salary);if(salary<=850)rate=0;else if(salary>1350 && salary<=2850)rate=0.1;else if(salary>2850 && salary<5850)rate=0.15;elserate=0.2;tax=rate*(salary-850);printf("salary=%f,rate=%f,tax=%f",salary,rate,tax);}3.3 循环控制一、填空题：1.222.233. 464.117二、选择题：CDBBB CCCBD三、程序阅读：1、输出：332、输出：243、2#4#7#11#16#4、3#2#0#0#1#5、BADC6、DABC7、BCAD8、ADBC9、CCA10、BDA11、ADC四、编程1．#include <stdio.h>#include <math.h>void main(){ int x;printf("x sqrt(x)\n");for(x=5;x<=1000;x++)printf("%d %f\n", x, sqrt(x));}2．#include<stdio.h>#include<math.h>main(){int i,flag;double pi,item;i=1;flag=1;pi=0;item=1.0;while(fabs(item)>=0.00001){ item=flag*1.0/i;pi=pi+item;flag=-flag;i=i+2;}pi=pi*4;printf("pi=%f",pi);}3．教材126页例6.84．#include<stdio.h>main(){ int i,a,b,c;a=1;b=1;printf("%d %d ",a,b);for(i=3;i<=10;i++){c=a+b;printf("%d ",c);a=b;b=c;}}第4章数组一、选择题：DDADC CDBDB DDDAB二、程序填空：ABBDCDABBBDCACDCA1#2#3#1#1#3298三、编程：1、#include <stdio.h>void main( ){int mark, a, p, f;a = p = f = 0;printf("Enter scores:");scanf ("%d", &mark);while (mark >0){if(mark >= 85) a++;else if (mark >= 60) p++;else f++;scanf ("%d", &mark);}printf(">=85:%d\n", a);printf("60-84:%d\n", p);printf("<60:%d\n", f);}2、#include <stdio.h>void main( ){ int a[10],count=0,i;float average,sum=0;for(i=0;i<10;i++){ scanf("%d",&a[i]);sum=sum+a[i];}average=sum/10;for(i=0;i<10;i++)if(a[i]>average) count=count+1;printf("平均值为%f 大于平均值的数有%d个",average,count); }3．#include<stdio.h>main( ){ int a[10];int i,j,t,n;printf(“请输入一个正整数n（1<n≤10）：”);scanf(“%d”,&n);for (i=0; i<n; i++)scanf("%d",&a[i]);printf("\n");for (j=0; j<n-1; j++) /*确定基准位置*/for(i=j+1; i<n; i++)if (a[j]>a[i]){ t=a[j];a[j]=a[i];a[i]=t; }printf("The sorted numbers: \n");for (i=0; i<n; i++)printf("%d",a[i]);}4．#include <stdio.h>void main(){int a[6][6],n,i,j,x,y,max;printf(“请输入一个正整数n（1≤n≤6）：”);scanf(“%d”,&n);printf(“请输入一个n行n列的矩阵：\n”);for (i=0;i<n;i++)for (j=0;j<n;j++)scanf(“%d”,&a[i][j]);max=a[0][0]; x=0;y=0;for (i=0;i<n;i++)for (j=0;j<n;j++)if (fabs(a[i][j])>max) {max=a[i][j];x=i;y=j;}printf(“绝对值最大的元素为：%d,下标分别为：%d,%d\n”,max,x,y); }第5章函数一、选择题ABCBDC7) BDAC8) DCBA9)DBB10) CCBB二、程序阅读题（1）3，5（2） 4（3）s=10（4）5，257,15三、程序设计1# include<stdio.h># include<math.h>int isprime(int m){ int k, n, res;if(m == 1) return 0;res = 1;n = (int)sqrt(m);for(k = 2; k <= n; k++)if(m%k == 0){res=0;break;}return res;}void main( ){int m,n;int sum=0;int i;do{printf("Input m,n m<n like:3,10\n");scanf("%d,%d",&m,&n);}while(m<0 || n<0 || m>n);for(i=m;i<=n;i++){if(isprime(i)){sum+=i;}}printf("The all primes' sum is:%d\n",sum); }2int max_value(int arr[][4]){int i,j,max;max=arr[0][0];for(i=0;i<2;i++)for(j=0;j<4;j++){if(max<a[i][j])max=a[i][j];}return max;}3# include<stdio.h># include<math.h>int isTheFineNumber(int n)int flag=0;int a,b,c;if((int)sqrt(n)==sqrt(n))//Íêȫƽ·½Êý{a=n%10;b=(n/10)%10;c=n/100;if(a==b||b==c||c==a)flag=1;}return flag;}void main(){int n;int i;scanf("%d",&n);for(i=101;i<n;i++)if(isTheFineNumber(i))printf("%d\n",i);}第7章预处理命令CBBBD DDBC第8章指针一、选择题：1、D2、A3、D4、A5、D6、B7、C8、D9、B10、 D11、 D二、程序阅读题：1、C2、A3、B4、C5、A三、程序设计题：1#include<stdio.h>void main(){ void swap(int *pointer1,int *pointer2);int *p1,*p2;int a=1,b=2;p1=&a;p2=&b;swap(p1,p2);printf("%d\n%d",a,b);}void swap(int *p1,int *p2){int temp;temp=*p1;*p1=*p2;*p2=temp;}2#include<stdio.h>void main(){ int a[10],*p1,i,j,temp;p1=a;for(i=0;i<10;i++)scanf("%d",p1+i);for(i=0;i<10;i++){p1=a;for(j=0;j<10-i;j++,p1++)if(*p1>*(p1+1))temp=*p1;*p1=*(p1+1);*(p1+1)=temp;}}p1=a;for(i=0;i<10;i++,p1++)printf("%d ",*p1);}3#include<stdio.h>void main(){int upper=0,lower=0,digit=0,space=0,other=0,i=0; char *p,s[20];printf("input string:");while((s[i]=getchar())!='\n') i++;p=&s[0];while(*p!='\n'){if(('A'<=*p)&&(*p<='Z'))++upper;else if (('a'<=*p)&&(*p<='z'))++lower;else if (*p==' ')++space;else if (('0'<=*p)&&(*p<='9'))++digit;else ++other;p++;}printf("upper case is:%d lower case:%d",upper,lower); printf("space: %d digit:%d other:%d",space,digit,other); }4strmcpy(char s[],char t[],int m){ char *p1,*p2,i;p1=s;p2=t+m;while(*p2!='\0'){p1++;p2++;}}5#include<stdio.h>void main(){int s[4][4]={1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16};int *p,i,j,t;p=&s[0][0];for(i=0;i<4;i++)for(j=i;j<4;j++){t=*(p+4*i+j);*(p+4*i+j)=*(p+4*j+i);*(p+4*j+i)=t;}}第9章结构体共用体一、选择题：1.D、D、D、D、C2. D3. A4.BC (选项B改为(*p).pk，结果为C)5. D二、选择填空题：1. B2. C三、编程题：1#include<stdio.h>struct{int year;int month;int day;}date;void main(){ int days;printf("input year,month,day:\n");scanf("%d%d%d",&date.year,&date.month,&date.day);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("%d/%d is the %dth day in %d\n",date.month,date.day,days,date.year); }2#include<stdio.h>struct{int hour;int min;int sec;}time1,time2,time3;void main(){printf("input the first time hour,min,sec:\n");scanf("%d%d%d",&time1.hour,&time1.min,&time1.sec);printf("input the second time hour,min,sec:\n");scanf("%d%d%d",&time2.hour,&time2.min,&time2.sec);time3.sec=time2.sec-time1.sec;if(time3.sec<0){time3.sec+=60;time2.sec--;}time3.min=time2.min-time1.min;if(time3.min<0){time3.min+=60;time2.min--;}time3.hour=time2.hour-time1.hour;printf("timelag is hour:%d min:%d sec:%d ",time3.hour,time3.min,time3.sec);}3#include<stdio.h>#define N 5struct student{char num[6];char name[6];int score[4];}stu[N];void main(){ void print(struct student stu[6]);int i,j;for(i=0;i<N;i++){printf("ninput score of student %d:\n",i+1);printf("No.: ");scanf("%s",stu[i].num);printf("name: ");scanf("%s",stu[i].name);for(j=0;j<3;j++){printf("score %d: ",j+1);scanf("%d",&stu[i].score[j]);}printf("\n");print(stu);}}void print(struct student stu[6])printf("\n No. name score1 score2 score3\n"); for(i=0;i<N;i++){printf("%5s%10s",stu[i].num,stu[i].name);for(j=0;j<3;j++)printf("%9d",stu[i].score[j]);printf("\n");}}第10章文件一、选择题C C B B A C CD D C D D D二、编程1.#include <stdio.h>#include <string.h>void main(){FILE *fp;char str[80];if((fp=fopen("test.txt","r"))==NULL)printf("error\n");while(!feof(fp)){fscanf(fp,"%s\n",str);if(strstr(str,"for")!=NULL)printf("%s\n",str);}fclose(fp);}2.#include <stdio.h>#include <string.h>void main(){FILE *fp;int n,sum=0;if((fp=fopen("in.txt","a+"))==NULL)printf("error\n");while(!feof(fp)){fscanf(fp,"%d\n",&n);sum+=n;fprintf(fp,"\nsum=%d\n",sum);fclose(fp);}3.#include <stdlib.h>#include <stdio.h>void main(int argc,char *argv[ ]){FILE *in,*out;char ch;if (argc!=3){printf("You forgot to enter a filename\n");exit(0);}if((in=fopen(argv[1],"r"))==NULL){printf("cannot open infile\n");exit(0);}if((out=fopen(argv[2],"w"))==NULL){printf("cannot open outfile\n");exit(0);}while(!feof(in)) fputc(fgetc(in),out);fclose(in);fclose(out);}4.#include <stdio.h>#include <string.h>void main(){FILE *fp;int n,a=0,b=0,c=0;if((fp=fopen("number.dat","a+"))==NULL)printf("error\n");while(!feof(fp)){fscanf(fp,"%d\n",&n);if(n>0)a++;else if(n<0)b++;else c++;}printf("正数有%d个，负数有%d个，零有%d个\n",a,b,c);fclose(fp);}。