实验一

#include<stdio.h>
int main()
{
    printf("201983270526\n");
    printf("Hello Mars!");
    return 0;
    
 }

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

#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<8)
      printf("weekend, relax~\n");
    else 
      printf("Ooops, not in 1~7\n");

    return 0; 
}

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