实验1

//判断奇偶 
  #include <stdio.h> 
  int main() {
      int x;
      
      printf("输入一个整数: \n");
      scanf("%d",&x);
      if( x/2==1,&x)  
          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<=5&&days>=1) // days在1到5之间
          printf("workdays, fighting\n");
      else if(days==6||days==7) // days是6或7
          printf("weekend, relax~\n");
      else
          printf("Ooops, not in 1~7\n");
      
      return 0;
  } 

//大小写 
  #include <stdio.h>
  int main() {
      char ch;
      
      printf("输入一个字符:\n");
      scanf("%c",&ch);
      if(ch<=122&&ch>=97)
          ch=ch-32; 
      printf("%c\n",ch);      
      return 0;
  }