我的这个用c语言写的，哪里错了，求解答！

Question

Answer 1

scanf("%d",x)改成scanf("%d",&x)

修改如下：

#include <stdio.h>
int main()
{
    int x,y,a;
    scanf("%d",&x);
    if(x<0)
        a = -1;
    else 
        a = x/10;
    switch(a)
    {
    case -1:
        y = x -2;
        break;
    case 0:
        y = 3*x;
        break;
    default:
        y = 4*x+1;
        break;
    }
    printf("%d",y);
    
    return 0;
}