请问这道题该如何编程

#include "stdio.h"
int main()
{
int nP = 0;

scanf("%d", &nP);

if (nP < 0) 
{
    printf("input error");
}
else if (nP >= 0 && nP <= 35)
{
    printf("excellent");
}
else if(nP > 35 && nP <= 75)
{
    printf("good");
}
else if(nP > 75 && nP <= 115)
{
    printf("light population");
}
else
{
    printf("medium and heavy population");
}

}