用switch case 匹配

#include <iostream>
using namespace std;

double choose(int x)
{
    switch (x)
    {
        case 1:
            return 4;
        case 2:
            return 4.5;
        case 3:
            return 5;
        case 4:
            return 2;
        case 5:
            return 1.5;
        default:
            return 0;
    }
}

int main()
{
    int x,y;
    cin >> x >> y;
    double res = 0;
    res += choose(x) * y;
    printf("Total: R$ %.2lf",res);
    return 0;
}