C语言程序设计，实验报告程序

判断输入字符种类
#include <stdio.h>
#include <stdlib.h>

int main()
{
char c;
printf("plz enter character:\n ");
c=getchar();
if(c<32){
printf("\n the charater is a control charater");
}else if(c>='0'&&c<='9'){
printf("\n the charater is a digit");
}else if(c>='A'&&c<='Z'){
printf("\n the charater is a capital letter");
}else if(c>='a'&&c<='z'){
printf("\n the charater is a lower letter");
}else {
printf("the charater is other charater");
}

}

2.输入三个数，从小到大排序#include <stdio.h>#include <stdlib.h>int main(){float a,b,c,d;printf("\n plz enter three number:");scanf("\n%f %f %f",&a,&b,&c);if(a>b){d=a; a=b; b=d;}if(a>c){d=a; a=c; c=d;}if(b>c){d=b; b=c; c=d;}printf("\n %5.1f,%5.1f,%5.1f\n",a,b,c);return 0;}

3.判断一年是否是闰年#include <stdio.h>#include <stdlib.h>int main(){int year,leap;printf("\n enter your year:");scanf("\n%d",&year);if((year%4==0&&year%100!=0)||(year%400==0)){leap=1;}else{leap=0;}if(leap){printf("\n%d is a leap year",year);}else{printf("\n%d is not a leap year",year);}return 0;}

4.输入两个数，判断是否相等#include <stdio.h>#include <stdlib.h>int main(){int a,b;printf("\n plz enter two numbles");scanf("\n%d %d",&a,&b);if(a==b){printf("\n a=b");}else{printf("\n a!=b");}}5.二元一次方程求根#include <stdio.h>#include <stdlib.h>#include<math.h>int main(){float a,b,c,disc,x1,x2,p,q;printf("plz enter a b c");scanf("%f %f %f",&a,&b,&c);disc=b*b-4*a*c;if(disc>0){p=-b/(2*a);q=sqrt(disc)/(2*a);x1=p+q;x2=p-q;printf("\n\nx1=%5.2f\nx2=%5.2f\n",x1,x2);}else{printf("\n\nmei you shigen\n\n");}}

6.字符大小写转换#include <stdio.h>#include <stdlib.h>int main(){char ch;printf("plz enter a charater\n");scanf("%c",&ch);ch=(ch>='A'&&ch<='Z')?(ch+32):(ch-32);printf("%c",ch);return 0;}

7.根据输入的字符输出相应的语句（switch-case练习！）#include <stdio.h>#include <stdlib.h>int main(){int c;printf("plz enter charater:\n");c=getchar();switch(c){case 'm':printf("good morning!\n");break;case 'n':printf("good night\n");break;case 'o':printf("other\n");break;default:printf("???\n");break;}return 0;}8.

要求按照考试成绩的等级输出百分制分数段，A等为85分以上，B等为70～84分，C等为60～69分 ，D等为 60分以下 。成绩的等级由键盘输入#include <stdio.h>int main(){ char grade;scanf("%c",&grade);printf("Your score:");switch(grade){ case 'A': printf("85～100\n");break;case 'B': printf("70～84\n");break;case 'C': printf("60～69\n");break;case 'D': printf("<60\n");break;default:  printf("enter data error!\n");}return 0;}9.编程实现：输入一个整数，判断它能否被3、5、7整除，并输出以下信息之一：能同时被3、5、7整除；能被其中两数（要指出哪两个）整除；能被其中一个数（要指出哪一个）个整除；不能被3、5、7任一个整除。#include <stdio.h>#include <stdlib.h>int main(){int a;printf("plz input a number:\n");scanf("%d",&a);if(a%3==0&&a%5==0&&a%7==0){printf("%d neng bei 3,5,7zhengchu!\n",a);}else if(a%3==0&&a%5==0){printf("%d nengbei 3,5 zhengchu\n",a);}else if(a%3==0&&a%7==0){printf("%d nengbei 3,7 zhengchu\n",a);}else if(a%7==0&&a%5==0){printf("%d nengbei 7,5 zhengchu\n",a);}else if(a%3==0){printf("%d nengbei 3, zhengchu\n",a);}else if(a%5==0){printf("%d nengbei 5, zhengchu\n",a);}else if(a%7==0){printf("%d nengbei 7, zhengchu\n",a);}return 0;}