实验1c语言的开发环境使用和数据类型，运算符，表达式

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

/*求两个整数的乘积*/
#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 ;
 }
 int product(int a,int b)
 {
     int mul;
     mul=a*b;
     return mul;
  } 

#include<stdio.h>
int main ()
{
    int a=,b=,c=,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 ;
 } 

#include<stdio.h>
int main()
{
    int a=,b=;
    printf("a++=%d\n",a++);
    printf("a=%d\n",a);
    printf("++b=%d\n",++b);
    printf("b=%d\n",b);
    return ;
 } 

#include<stdio.h>
int main()
{
    int a=,b=,c=;
    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>=c),!(a<=b));
    return ;
}

#include<stdio.h>
int main()
{
    int x;
    printf("输入一个整数：\n");
    scanf("%d",&x);

    if (x%==)
    printf("是奇数");
    else
    printf("是偶数");

    return ;
}

#include<stdio.h>
int main()
{
    int days;

    printf("输入一个整数:\n");
    scanf("%d",&days);

    if(days>=&&days<===)
    printf("workdays,fighting\n");
    else if(days>=&&days<===)
    printf("weekend,relex~\n");
    else
    printf("Ooops,not in 1~7\n");

    return ;
}

#include<stdio.h>
int main()
{
    char ch;

    printf("输入一个字符:\n");
    scanf("%c",&ch);

    if(ch>='a'&&ch<='z'==)
    printf("%c\n",ch-);

    return ;
 }