实验1 C语言运行环境的使用和数据类型、运算符和表达式

//判断奇偶性
#include <stdio.h>
int main ()
{ 
   int x;
   printf("输入一个整数：\n");
   scanf("%d",&x);
   if(x%2!=0)
   printf("是奇数");
   else
   printf("是偶数");
   return 0; 
   

 } 

#include<stdio.h>
int main()
{
    int days;
    printf("输入一个整数:\n");
    scanf("%d",&days);
    if(days>=1&&days<=5)
    printf("workdays,fighting\n");
    else if("days==6||days==7")
    printf("weekend,relax~\n");
    else
    printf("Ooops,not in 1~7\n");
    return 0;
    
}

//判断字母大小写
#include <stdio.h>
 int main ()
 {
     char ch;
     printf("输入一个字符:\n");
     scanf("%c",&ch);
     if(ch>=‘a‘&&ch<=‘z‘)
     ch=ch-32;
     printf("%c\n",ch);
     return 0;
 }