c语言程序设计课后习题答案C语言程序设计课后习题答案C语言是一门广泛应用于计算机科学和软件开发领域的编程语言。
学习C语言的过程中，课后习题是非常重要的一部分，通过解答习题可以加深对所学知识的理解和掌握。
本文将为大家提供一些C语言程序设计课后习题的答案，希望能对大家的学习有所帮助。
1. 编写一个程序，输入一个整数，判断该整数是否为奇数。
答案：```c#include <stdio.h>int main() {int num;printf("请输入一个整数：");scanf("%d", &num);if (num % 2 == 0) {printf("该整数是偶数\n");} else {printf("该整数是奇数\n");}return 0;}```2. 编写一个程序，输入一个字符，判断该字符是否为字母。
答案：```c#include <stdio.h>int main() {char ch;printf("请输入一个字符：");scanf("%c", &ch);if ((ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z')) { printf("该字符是字母\n");} else {printf("该字符不是字母\n");}return 0;}```3. 编写一个程序，输入一个年份，判断该年份是否为闰年。
答案：```c#include <stdio.h>int main() {int year;printf("请输入一个年份：");scanf("%d", &year);if ((year % 4 == 0 && year % 100 != 0) || year % 400 == 0) {printf("该年份是闰年\n");} else {printf("该年份不是闰年\n");}return 0;}```4. 编写一个程序，输入一个正整数，计算并输出该正整数的阶乘。
2.2 #include<stdio.h>main(){float x=2.5,y=2.5,z=2.5;printf("x=%f\n",x);printf("y=%f\n",y);printf("z=%f\n",z);}3.1(1) #include<stdio.h>main(){int a=12,b=3;float x=18.5,y=4.6;printf("%d\n",(float)(a*b)/2);printf("%d\n",(int)x%(int)y);}3.2 #include<stdio.h>main(){int x,b0,b1,b2,s;printf("Inputx:");scanf("%d",&x);b2=x/100;b1=(x-b2*100)/10;b0=x%10;s=b0*100+b1*10+b2;printf("s=%d\n",s);}3.3 #include<stdio.h>#include<math.h>main(){float rate=0.0225;float n,capital,deposit;printf("Input n,capital:"); scanf("%f,%f",&n,&capital); deposit=capital*pow(1+rate,n); printf("deposit=%f\n",deposit); }3.4 #include<stdio.h>#include<math.h>main(){float a,b,c;double x,y;printf("Inputa,b,c:");scanf("%f,%f,%f",&a,&b,&c);x=(-b+sqrt(b*b-4*a*c))/(2*a);y=(-b-sqrt(b*b-4*a*c))/(2*a); printf("x=%f,y=%f\n",x,y);}4.1(1) #include<stdio.h>main(){char c1='a',c2='b',c3='c'; printf("a%cb%cc%c\n",c1,c2,c3); }4.1(2) #include<stdio.h>main(){int a=12,b=15;printf("a=%d%%,b=%d%%\n",a,b); }4.1(3) #include<stdio.h>main(){int a,b;scanf("%2d%*2s%2d",&a,&b); printf("%d,%d\n",a,b);}4.2 #include<stdio.h> main(){long a,b;float x,y;scanf("%d,%d\n",&a,&b); scanf("%f,%f\n",&x,&y); printf("a=%d,b=%d\n",a,b); printf("x=%f,b=%f\n",x,y); }5.1 #include<stdio.h> main(){float a;printf("Innputa:");scanf("%f",&a);if(a>=0){a=a;printf("a=%f\n",a);}else{a=-a;printf("a=%f\n",a);}}5.2 #include<stdio.h> main(){int a;printf("Inputa:"); scanf("%d",&a);if(a%2==0){printf("a是偶数");}else{printf("a是奇数");}}5.3 #include<stdio.h>#include<math.h>main(){float a,b,c,s,area;printf("Inputa,b,c:");scanf("%f,%f,%f",&a,&b,&c);if(a+b>c&&a+c>b&&b+c>a){s=(a+b+c)/2;area=(float)sqrt(s*(s-a)*(s-b)*(s-c)); printf("area=%f\n",area);}else{printf("不是三角形");}}5.4 #include<stdio.h>#include<math.h>main(){float a,b,c,x,y;printf("Inputa,b,c:");scanf("%f,%f,%f",&a,&b,&c);if(a==0){printf("该方程不是一元二次方程\n"); }if(b*b-4*a*c>0){x=(-b+sqrt(b*b-4*a*c))/(2*a);y=(-b-sqrt(b*b-4*a*c))/(2*a); printf("x=%f,y=%f\n",x,y);}else if(b*b-4*a*c==0){x=-b/(2*a);y=-b/(2*a);printf("x=%f,y=%f\n",x,y);}else{printf("该方程无实根\n");}}5.5 #include<stdio.h>main(){int year,flag;printf("Input a year:");scanf("%d",&year);if(year%4==0&&year%400!=0||year%400==0) {flag=1;}else{flag=0;}if(flag==1){printf("%d is a leap year !\n",year);}else{printf("%d is not a leap year !\n",year);}}5.6 #include<stdio.h>main(){int year,flag;printf("Input a year:");scanf("%d",&year);flag=year%400==0||year%4==0&&year%100!=0?1:0; if(flag==1&&flag!=0){printf("%d is a leap year !\n",year);}else{printf("%d is not a leap year !\n",year);}}5.7 #include<stdio.h>main(){char ch;printf("Inputch:");scanf("%c",&ch);if(ch>='a'&&ch<='z'){ch=getchar();ch=ch-32;printf("%c,%d\n",ch,ch);}else if(ch>='A'&&ch<='Z') {ch=getchar();ch=ch+32;printf("%c,%d\n",ch,ch);}else{printf("%c",ch);}}5.8 #include<stdio.h>main(){char ch;printf("Inputch:");scanf("%c",&ch);if(ch>=48&&ch<=57){printf("ch是数字字符\n");}else if(ch>=65&&ch<=90) {printf("ch是大写字母\n");}else if(ch>=97&&ch<=122) {printf("ch是小写字母\n");}else if(ch==32){printf("ch是空格\n");}else{printf("ch是其他字符\n");}}5.9 #include<stdio.h>main(){int score,grade;printf("Input score:");scanf("%d",&score);grade=score/10;if(score<0||score>100){printf("Input error\n");}if(score>=90&&score<=100) {printf("%d--A\n",score);}else if(score>=80&&score<90) {printf("%d--B\n",score);}else if(score>=70&&score<80){printf("%d--C\n",score);}else if(score>=60&&score<70){printf("%d--D\n",score);}else if(score>=0&&score<60){printf("%d- -E\n",score);}}5.10 #include<stdio.h>main(){int year,month;printf("Input year,month:");scanf("%d,%d",&year,&month); if(month>12||month<=0){printf("error month\n");}else{switch(year,month){case 12:case 10:case 8:case 7:case 5:case 3:case 1:printf("31天\n");break;case 11:case 9:case 6:case 4:printf("30天\n");break;case 2:if(year%4==0&&year!=0||year%400==0) {printf("29天\n");}else{printf("28天\n");}break;default:printf("Input error\n");}}}6.1(1) #include<stdio.h>main(){int i,j,k;char space=' ';for(i=1;i<=4;i++){for(j=1;j<=i;j++){printf("%c",space);}for(k=1;k<=6;k++){printf("*");}printf("\n");}}6.1(2) #include<stdio.h> main(){int k=4,n;for(n=0;n<k;n++){if(n%2==0) continue;k--;}printf("k=%d\n,n=%d\n",k,n); }6.1(3) #include<stdio.h> main(){int k=4,n;for(n=0;n<k;n++){if(n%2==0) break;k--;}printf("k=%d,n=%d\n",k,n); }6.2(1) #include<stdio.h> main(){int i,sum=0;for(i=1;i<=101;i++){sum=sum+i;}printf("sum=%d\n",sum);}6.2(2) #include<stdio.h>main(){long i;long term,sum=0;for(i=1;i<=101;i=i+2){term=i*(i+1)*(i+2);sum=sum+term;}printf("sum=%ld\n",sum);}6.2(4) #include<stdio.h>#include<math.h>main(){int n=1;float term=1.0,sign=1,sum=0; while(term<=-1e-4||term>=1e-4) {term=1.0/sign;sum=sum+term;sign=sign+n;n++;}printf("sum=%f\n",sum);}6.2(5) #include<stdio.h> #include<math.h>main(){int n=1,count=1;float x;double sum,term;printf("Input x:");scanf("%f",&x);sum=x;term=x;do{term=-term*x*x/((n+1)*(n+2)); sum=sum+term;n=n+2;count++;}while(fabs(term)>=1e-5);printf("sin(x)=%f,count=%d\n",sum,count); }6.3 #include<stdio.h>main(){int x=1,find=0;while(!find){if(x%2==1&&x%3==2&&x%5==4&&x%6==5&&x%7==0) {printf("x=%d\n",x);find=1;x++;}}}/*int x,find=0;for (x=1;!find;x++){if(x%2==1&&x%3==2&&x%5==4&&x%6==5&&x%7==0) {printf("x=%d\n",x);find=1;}}}*/6.4 #include<stdio.h>main(){int i,n;long p=1,m=1;printf("Input n:");scanf("%d",&n);for(i=1;i<=n;i++){p=i*i;m=i*i*i;printf("p=%d,m=%d\n",i,p,i,m); }}6.5 #include<stdio.h>main(){float c,f;for(c=-40;c<=110;c=c+10) {f=9/5*c+32;printf("f=%f\n",f);}}6.6 #include<stdio.h> #include<math.h>main(){int n;double c=0.01875,x;do{x=x*pow(1+c,12)-1000;n++;}while(x>0);printf("x=%d\n",x);}6.7 #include<stdio.h> main(){int n=0;float a=100.0,c;printf("Inputc:");scanf("%f",&c);do{a=a*(1+c);n++;}while(a<=200);printf("n=%d\n",n);}6.8 #include<stdio.h>#include<math.h>main(){int n=1,count=1;double sum=1,term=1;while(fabs(term)>=1e-5){term=pow(-1,count)*(1.0/(n+2)); sum=sum+term;n=n+2;count++;}sum=4*sum;printf("sum=%f,count=%d\n",sum,count); }6.9 #include<stdio.h>#include<math.h>main(){int n=1,count=1;double sum=1,term=1;while(fabs(term)>=1e-5){term=term*(1.0/n);sum=sum+term;n++;count++;}printf("sum=%f,count=%d\n",sum,count); }6.10 #include<stdio.h>#include<math.h>main(){int x;for(x=100;x<=999;x++){if(x==pow(x/100,3)+pow(x/10%10,3)+pow(x%10,3)) printf("x=%d\n",x);}}6.11 #include<stdio.h>main(){int i=0,n;long sum=0,term=1;printf("Inputn:");scanf("%d",&n);do{i++;term=term*i;sum=sum+term;}while(sum<n);printf("%d\n",i-1);6.12 #include<stdio.h>main(){int i,n,m,count=0,sum=0;printf("Input n:");scanf("%d",&n);for(i=1;i<=n;i++){printf("Inputm:");scanf("%d",&m);if(m>0){sum=sum+m;count++;}else{break;}printf("sum=%d,count=%d\n",sum,count); }6.13 #include<stdio.h>main(){int i,n,m,count=0,sum=0;printf("Inputn:");scanf("%d",&n);for(i=1;i<=n;i++){printf("Inputm:");scanf("%d",&m);if(m>0||m<0){sum=sum+m;count++;}else{break;}printf("sum=%d,count=%d\n",sum,count); }6.14 #include<stdio.h>main(){int x,y,z;for(x=0;x<=17;x++){for(y=0;y<=25;y++){3*x+2*y+z==50;z=30-x-y;if(3*x+2*y+z==50&&x+y+z==30) printf("x=%d,y=%d,z=%d\n",x,y,z); }}}6.15 #include<stdio.h>main(){int x,y;for(x=0;x<=98;x++){y=98-x;2*x+4*y==386;if(x+y==98&&2*x+4*y==386){printf("x=%d,y=%d\n",x,y);}}}6.16 #include<stdio.h>main(){int x,y,z;for(x=0;x<=20;x++){for(y=0;y<=33;y++){3*y+5*x+z/3.0==100;z=100-x-y;if (5*x+3*y+z/3.0==100&&z+x+y==100){printf("x=%d,y=%d,z=%d\n",x,y,z); }}}}6.17 #include<stdio.h>main(){int x,y,z;for(x=1;x<=9;x++){for(y=1;y<=17;y++){10*x+5*y+z==100;z=50-x-y;if(10*x+5*y+z==100&&x+y+z==50&&z>0) {printf("x=%d,y=%d,z=%d\n",x,y,z); }}}}7.1 #include<stdio.h>int Square(int i)return i*i;}int main(){int i=0;i=Square(i);for( ;i<3;i++){static int i=1;i+=Square(i);printf("%d,",i);}printf("%d\n",i); return 0;}7.2 #include<stdio.h> int hour,minute,second; void update(){second++;if(second==60)second=0;minute++;}if(minute==60){minute=0;hour++;}if(hour==24)hour=0;}void display(){printf("%d,%d,%d\n",hour,minute,second); }void delay(){int t;for(t=0;t<100000000;t++);}int main()int i;void updaye(),display(),delay(); for(i=0;i<1000000;i++){update();display();delay();}return 0;}7.3 #include<stdio.h>int GetMax(int a,int b);int main(){int x,y,max;printf("Inputx,y:");scanf("%d,%d",&x,&y);max=GetMax(x,y);printf("max=%d\n",max);return 0;}int GetMax(int m,int n) {if(m>=n)return m;elsereturn n;}7.4 #include<stdio.h> int LCM(int n,int m);int main(){int a,b;printf("Inputa,b:"); scanf("%d,%d",&a,&b); printf("%d\n",LCM(a,b)); return 0;}int LCM(int n,int m){int x;int find=0;for(x=1;!find;x++)if(x%n==0&&x%m==0){find=1;}}return x-1;}7.5 #include<stdio.h>long Fact(int n);int main(){int m,a;printf("Inputm:");scanf("%d",&m);for(a=1;a<=m;a++){printf("%d!=%ld\n",a,Fact(a)); }return 0;}long Fact(int n)int i;long result=1;for(i=2;i<=n;i++)result*=i;return result;}7.6 #include<stdio.h> long Fact(int n);int main(){int m;long ret;printf("Inputm:"); scanf("%d",&m);ret=Fact(m);printf("ret=%d\n",ret); return 0;}long Fact(int n){int i;long result=1,sum=0;for(i=2;i<=n;i++){result*=i;sum=sum+result;}return sum;}7.7(1) #include<stdio.h> int Gcd(int a,int b);int main(){int m,n;printf("Inputm,n:"); scanf("%d,%d",&m,&n); printf("%d\n",Gcd(m,n)); return 0;}int Gcd(int a,int b){int t,min,find=0;min=a<b?a:b;t=min;for(t=min;!find;t--){a%t==0;b%t==0;if(a%t==0&&b%t==0)return t;}find=1;}7.7(2) #include<stdio.h> int Gcd(int a,int b);int main(){int m,n;printf("Inputm,n:");scanf("%d,%d",&m,&n); printf("%d\n",Gcd(m,n)); return 0;}int Gcd(int a,int b){int r,temp;r=a%b;if(r==0)return b;elsedo{temp=b;b=r;a=temp;r=a%b;}while(r!=0);return b;}8.1(1) #include<stdio.h> void Func(int x){x=2;}int main(){int x=10;Func(x);printf("%d",x);return 0;}8.1(2) #include<stdio.h> void Func(int b[]){int j;for(j=0;j<4;j++){b[j]=j;}}int main(){static int a[]={5,6,7,8},i; Func(a);for(i=0;i<4;i++){printf("%d",a[i]);}return 0;}8.2(1) int PositiveNum(int a[],int n) {int i,count=0;for(i=0;i<n;i++){if(a[i]>0)count++;}return 0;}8.2(2) void Fib(long f[],long n){int i;f[0]=0;f[1]=1;for(i=2;i<n;i++){f[i]=f[i-1]+f[i-2];}}8.2(3) #include<stdio.h>int main(){int a[10],n,max,min,maxPos,minPos;for(n=0;n<10;n++){scanf("%d",&a[n]);}max=min=a[0];maxPos=minPos=0;for(n=0;n<10;n++){if(a[n]>max){max=a[n];maxPos=n;}else if(a[n]<min){min=a[n];minPos=n;}}printf("max=%d,pos=%d\n",max,maxPos); printf("min=%d,pos=%d\n",min,minPos);}8.3 void DivArray(int *pArray,int n){int i;for(i=0;i<n;i++){pArray[i]/=pAttay[0];}}8.4 #include<stdio.h>#define N 40int FailNum(int score[],int n);void ReadScore(int score[],int n);int main(){int score[N],n;printf("Input n:");scanf("%d",&n);ReadScore(score,n);FailNum(score,n);printf("FailNum students are %d\n",FailNum(score,n));}int FailNum(int score[],int n){int i,count=0;for(i=0;i<n;i++){if(score[i]<60)count++;}return count;}void ReadScore(int score[],int n) {int i;printf("Input score:");for(i=0;i<n;i++){scanf("%d",&score[i]);}}8.5 #include<stdio.h>#define N 40int HighAver(int score[],int n);int ReadScore(int score[]);int main(){int score[N],n;n=ReadScore(score);printf("HighAver students are %d\n",HighAver(score,n));return 0;}int HighAver(int score[],int n){int i,count=0,sum=0,aver;for(i=0;i<n;i++){sum=sum+score[i];aver=sum/n;}for(i=0;i<n;i++){if(score[i]>aver)count++;}return count;}int ReadScore(int score[]){int i=-1;do{i++;printf("Input score:");scanf("%d",&score[i]);}while(score[i]>=0);return i;}8.6 #include<stdio.h>#define N 40int ReadScore(int score[],long num[]);int FindMax(int score[],long num[],int n); int main(){int score[N],n,max,num,t;long num[N];t=FindMax(score,n);max=score[t];num=num[t];printf("max=%d,num=%d\n",max,num);return 0;}int ReadScore(int score[],long num[]){int i=-1;do{i++;printf("Input student's ID and score:"); scanf("%ld%d",&num[i],&score[i]);}while(num[i]>0&&score[i]>=0);return i;}int FindMax(int score[],long num[],int n) {int max,i;max=score[0];for(i=1;i<n;i++){if(score[i]>max)max=score[i];}return i;}8.7 #include<stdio.h>#define N 40int Read(int a[]);int ChangeArry(int a[],int n); int main(){int a[N],n;printf("%d\n",ChangeArry(a,n)); return 0;}int Read(int a[]){int i;for(i=0;i<9;i++){printf("Input a:");scanf("%d",&a[i]);return i;}int ChangeArry(int a[],int n){int max,min,i,maxpos,minpos,term; max=min=score[0];for(i=1;i<n;i++){if(a[i]>max)max=score[i];maxpos=n;else(a[i]<min)min=a[i];minpos=n;temp=maxpos;maxpos=minpos;minpos=temp;}return a[i];}8.10 #include<stdio.h>#define N 5void main(){int a[N][N];int sum = 0;int i, j;printf("请输入一个%d*%d的矩阵\n",N,N); for(i = 0; i < N; i++){for(j = 0; j < N; j++){scanf("%d",&a[i][j]);}}for(i = 0; i < N; i++){for(j = 0; j < N; j++){if(i == j || i + j == N - 1)sum=sum+a[i][j];}}printf("对角线元素之和为：%d\n",sum);。
c语⾔程序设计第三版苏⼩红_C语⾔学习⽇志（三）参考资料：C语⾔程序设计（第三版）练习⽹站：PTA第三章：分⽀结构任何程序都可以使⽤三种基本的控制结构来实现，即顺序结构，分⽀结构和循环结构。
⼆分⽀结构与多分⽀结构（if型）例3-1//简单的猜数游戏3-2：//判断整数的奇偶性例3-3//输⼊⼀批学⽣的成绩，计算平均分，并统计不及格的学⽣⼈数例3-4//计算多分段函数以上是多种分⽀结构在实际程序中的使⽤。
字符型数据及其输⼊与输出3-5：//求解简单的四则运算表达式1:字符型常量每个字符都有唯⼀的次序之，即ASCII码2：字符型变量字符型变量在定义时⽤类型名char，例如:char = op;定义了⼀个字符型变量op，它的值是字符型数据。
op='+'将字符型常量‘+’赋给字符型变量op。
3：字符型数据的输⼊与输出字符型数据的输⼊输出可以调⽤函数scanf(),printf(),getchar(),putchar().注：在上述函数调⽤的过程中，格式控制字符串中相应的格式控制说明为%cgetchar()可以从键盘输⼊⼀个字符，putchar()可以从键盘输出⼀个字符逻辑运算C语⾔提供了三种逻辑运算符：单⽬：！ 逻辑⾮双⽬：&& 逻辑与 和 || 逻辑或！a：如果a为真，则结果为假；如果a为假，则结果为真。
a&&b：当a和b都为真时，结果为真；否则结果为假。
a||b：当a和b都为假时，结果为假；否则结果为真。
例3-6：//统计字符，包括英⽂字母，数字字符和其他字符switch语句3-8：//查询⾃动售货机中商品的价格switch语句可以处理多分⽀选择问题，根据其中break语句的使⽤⽅法，⼀般分为三种情况1：在switch语句的每个语句段中都使⽤break语句switch注：switch语句中的default可以省略，如果省略了default，当表达式的值与任何⼀个常量表达式的值都不相等时，就什么都不执⾏。
