C++ :

#include <iostream>
using namespace std;
int main() {
    int currency;
    double amount;
    cin >> currency >> amount;
    switch (currency) {
        case 1: cout << "转换后的金额： " << amount * 7 << " 人民币"; break;
        case 2: cout << "转换后的金额： " << amount / 7 << " 美元"; break;
        default: cout << "无效的选择";
    }
    return 0;
}