实验1 C语言开发环境使用和数据类型，运算符，表达式

#include<stdio.h>
int main()
{
    printf("201983270564"):
    return 0;
}

#include<stdio.h>
int product(int,int);
int main(void)
{
    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 a=5,b=7,c=100,d,e,f;
    d=a/b*c;
    e=a*c/b;
    f=c/b*a;
    printf("d=%d,e=%d,f=%d\n",d,e,f);
    return 0;
}

#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;
}

#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()
{
    int days;
    printf("输入一个整数:\n");
    scanf("%d",&days);
    if(days<=5&&days>=1)
    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 main()
{
    char ch;
    printf("输入一个字符:\n");
    scanf("%c",&ch);
    if(ch>='a'&&ch<='z')
    ch-=32;
    
    printf("%c",ch);
    return 0;
}