实验1C语言开发环境使用和数据类型、运算符、表达式

# 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 ;
}

#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, relax~\n");
else
printf("Ooops, not in 1~7\n");
return ;
}

//关系运算和逻辑运算
# 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>=b),!(a>=c),!(a<=b));
    return ;
 } 

/*Thhis is first C program*/
# include<stdio.h>
int main()
{
    printf("headbchsajhcuiknlxkns");
    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 x;
  printf("输入一个整数: \n");
  scanf("%d",&x);

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

/*整数相除*/
# 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 ;
 } 

/*自加、自减运算*/
# 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 ;
 }