用C语言求分段函数的值

f（x）=0 x＜0
f（x）=2x+1 x≥0

if(x<0){f（x）=0}else{f（x）=2*x+1}

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

#include <stdio.h>
int main()
{
    double x,y;
    scanf("%lf",&x);
    if(x<0)
      y = 0;
    else
      y = 2*x+1;
    printf("%lf",y);
}