实验1 ljc

#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;
  }

　　

#include<stdio.h>
int product(int,int);
int main(void)
  {
  	int x,y,z;
	 scanf ("%d %d",&x,&y);
	  z=product(x,y);
	  printf("The mul is:%d",z);
	   return 0;
  }
  int product(int a ,int b)
  {
  	int mul;
  		mul=a*b;
  		return mul;
  }

　　

//This is the first C program
# include<stdio.h>
int main()
{
    printf("我来殖民了

!");
    return 0;
}

//关系运算和逻辑运算
# include<stdio.h>
int main()
{
    int a=5,b=8,c=8;
    printf("%d,%d,%d,%d\n",a==b&&a==c,a!=b&&a!=c,a>=b&&a>=c,a<=b&&a<=c);
    printf("%d,%d\n",a<=b||a>=c,a==b||b==c);
    printf("%d,%d,%d,%d\n",!(a==b),!(a>=b),!(a>=c),!(a<=b));
    return 0;
 } 

　　

#include<stdio.h>
int main(){
    int x;
    printf("输入一个整数：\n");
    scanf("%d",&x);
    
    if(x%2==1)
    
    printf("是奇数");
    
    else
    
    printf("是偶数");
    
    return 0;
}
   
    

# 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-'a'+'A'; 
printf("%c\n",ch);
return 0;
}

//自加、自减运算
#include<stdio.h>
int main()
{
    int a=5,b=8;
    printf("a++=%d\n",a++);
    printf("a=%d\n",a);
    printf("++b=%d\n",++b);
    printf("b=%d\n",b);
    return 0;
 }