20分求助！！！#1 #2 #4 #5

#include<bits/stdc++.h>
using namespace std;
int main(){
    int n;
    int a=150*0.4463,b=250*0.4663;
    cin>>n;
    if(n<=150)
        printf("%.1lf",n*0.4463);
    else if(n>150&&n<=400) 
        printf("%.1lf",a+(n-150)*0.4663);
    else 
        printf("%.1lf",a+b+(n-400)*0.5663);
    return 0;
}