#include <iostream> #include <cmath> #include <iomanip> using namespace std; int main() { int km; cin >> km; double money = 0.0; // 计算逻辑 if(km <= 2) { money = 6; } else { money = 6; if(km > 10) { money += 8 * 1.8; } else { money += (km - 2) * 1.8; } if(km > 10) { money += (km - 10) * 2.7; } }