题解 | 进制转换

#include <iostream>
using namespace std;

int main() {
    string str;
    cin >> str;
    int num = 0;
    
    string hex = str.substr(2);
    for(int i=0; i<hex.size(); i++)
    {
        int value;
        if ( '0' <= hex[i] && hex[i] <= '9'){
            value = hex[i] - '0';
        }
        else{ //处理大写字母
            value = 10 + hex[i] - 'A';
        }
        num = num*16 + value;

    }
    cout << num;

}