这两个代码怎么打求会的大神教我

#include <stdio.h>
int main()
{
    float x,y;
    scanf("%f",&x);
    if(x>9)
        y = -1;
    else if(x>3)
        y = x*(x+2);
    else if(x>-1)
        y = 2*x;
    else
        y = x-1;
    printf("%f",y);
    return 0;
}