题解 | 进制转换

#include <iostream>
using namespace std;

int main() {
    string hex;
    while (cin >> hex) { // 注意 while 处理多个 case

        int sum = 0;
        int temp;
        for (int i = 2; i < hex.size(); i ++) {
            if (hex[i] >= 'A' && hex[i] <= 'F') {
                temp = hex[i] - 'A' + 1 + 9;
            }
            if (hex[i] >= '0' && hex[i] <= '9') {
                temp = hex[i] - '0';
            }

            sum = sum * 16 + temp;
        }
        cout << sum << endl;
    }

    return 0;
}
// 64 位输出请用 printf("%lld")