实验1

 #include <stdio.h>
  int main() {
      int x;
      
      printf("输入一个整数: \n");
      scanf("%d",&x);
      int y;
      y==x%2;  
      if(y==1)  
          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)
          printf("学习\n");
      else if(days==7||days==6) 
          printf("休息\n");
      else
          printf("Ooops, not in 1~7\n");
      
      return 0;
  } 

  #include <stdio.h>
  int main() {
      char ch,b;
      
      printf("输入一个字符:\n");
      scanf("%c",&ch);
      if(ch>='a'&&ch<='z') 
      printf("%c\n",ch-'a'+'A');  
    else
      printf("%c\n",ch);
      
      return 0;
  }