刷题05：HJ5

#include <iostream>
#include <cmath>
using namespace std;

int main()
{
    
    
    string s;
    while (cin >> s) {
    
    
        int len = s.length()-2; //去掉开始输入的'0'与'X'
        int temp = 0;
        int D = 0;
        for (int i = 2; i < len+2; i++) {
    
    
            switch (s[i])
            {
    
    
            case 'A': temp = 10; break;
            case 'B': temp = 11; break;
            case 'C': temp = 12; break;
            case 'D': temp = 13; break;
            case 'E': temp = 14; break;
            case 'F': temp = 15; break;
            default: temp = s[i] - '0'; break;
            }
            D += (temp * pow(16, len + 1 - i));
        }
        cout << D << endl;
    }
    return 0;
}