题解 | #进制转换#

#include <iostream>
#include <stack>
#include <string>
using namespace std;

int main() {
    char c;
    stack<char> cStack;
    while (cin >> c) {
        cStack.push(c);
    }

    int index = 1;
    int res = 0;
    while (cStack.size() > 0 && c != 'x') {
        c = cStack.top();
        
        if (c != 'x') {
            if (c >= 'A')
                res += (c - 'A' + 10) * index;
            else
                res += (c - '0') * index;
        }

        index *= 16;
        cStack.pop();
    }
    cout << res;
}
// 64 位输出请用 printf("%lld")