题解 | #计算商品打折结算金额#

#include <iostream>
#include <iomanip>
using namespace std;

int main() {
    
    double price;
    cin >> price;

    double cost = 0.0;

    // write your code here.......
    if(price>=100&&price<500)
        cost=price*0.9;
    else if(price>=500&&price<2000)
        cost=price*0.8;
    else if(price>=2000&&price<5000)
        cost=price*0.7;
    else if(price>=5000)
        cost=price*0.6;

    cout << setiosflags(ios::fixed) << setprecision(1) << cost << endl;//其中setprecision()为了精确小数位数，setiosflags(ios::fixed)为了保证当只有一位小数位且该小数位是0时，避免用e的指数输出

    return 0;
}