可是不能输出正确的结果：
#include<stdio.h>
void main()
{
int x,y;
printf("please input x\n");
scanf("%d",&x);
if(x<1)
{
y=x;
printf("x=%d,y=x=%d\n");
}
else if(x<10)
{
y=2*x-1;
printf("x=%d,y=2*x-1=%d\n");
}
else
{
y=3*x-11;
printf("x=%d,y=3*x-11=%d\n");
}
}

#include<stdio.h>
void main()
{
int x,y;
printf("please input x\n");
scanf("%d",&x);
if(x<1)
{
y=x;
printf("x=%d,y=x=%d\n");           /*  明显漏了格式化输出的变量  正确为：printf("x=%d,y=x=%d\n",x,y);  */
*/
}

}
else if(x<10)
{
y=2*x-1;
printf("x=%d,y=2*x-1=%d\n");   /*  明显漏了格式化输出的变量  正确为：printf("x=%d,y=2*x-1=%d\n",x,y);  */
}
else
{
y=3*x-11;
printf("x=%d,y=3*x-11=%d\n");  /*  明显漏了格式化输出的变量  正确为：printf("x=%d,y=3*x-11=%d\n",x,y);  
}
}

#include "stdio.h"
int jisuan(int x)
{
    int y;
    if(x<1)
    y=x;
    else if(x>=1 && x<10)
    y=2*x-1;
    else
    y=3*x-11;
    return y;

}

main()
{
    int x;
    scanf("%d",&x);
    printf("y的值为：%d",jisuan(x));
}

已改正，谢谢你~

已调试，谢谢你~

我记住了，以后再犯这种低级错误我会扇自己耳光的！

#include<stdio.h>
void main()
{
int x,y;
printf("please input x\n");
scanf("%d",&x);
if(x<1)
{
y=x;
printf("x=%d,y=x=%d\n",x,y);
}
else if(x<10)
{
y=2*x-1;
printf("x=%d,y=2*x-1=%d\n",x,y);
}
else
{
y=3*x-11;
printf("x=%d,y=3*x-11=%d\n",x,y);
}
}

试一试，还行  呵呵

[ 本帖最后由 sweet1231990 于 2010-5-22 11:51 编辑 ]

#include<stdio.h>
void main()
{
int x,y;
printf("please input x\n");
scanf("%d",&x);
if(x<1)
{
y=x;
printf("x=%d,y=x=%d\n",x,y);
}
else if(x<10)
{
y=2*x-1;
printf("x=%d,y=2*x-1=%d\n",x,y);
}
else
{
y=3*x-11;
printf("x=%d,y=3*x-11=%d\n",x,y);
}
}
你忘写需要输出的数的，己用红色标出来了。