题解 | #进制转换#

#include <string>
#include <iostream>
#include <map>
#include <cmath>

using namespace std;
int main() {
    string str;
    map<char, int> myMap = {{'0', 0}, {'1', 1}, {'2', 2}, {'3', 3}, {'4', 4},
        {'5', 5}, {'6', 6}, {'7', 7}, {'8', 8}, {'9', 9},
        {'A', 10}, {'B', 11}, {'C', 12}, {'D', 13}, {'E', 14}, {'F', 15}
    };

    while (cin >> str) {
        double sum = 0;
        for (int i = 2, j = str.size() - 3; i < str.size() ; ++i) {
            sum += myMap[str[i]] * pow(16, j);
            j--;
        }
        cout << (int)sum << endl;
    }
}