题解 | #进制转换#

#include<iostream>
#include<string>
#include<math.h>
using namespace std;
int main(){
    string str;
    while(cin >> str){
        int len = str.size()-1, n=0;
        for(int i = len; i > 1; --i){
            if('0' <= str[i] && str[i] <= '9')
                n += (int)(str[i]-'0')*pow(16,len-i);
            else
                n += (int)(str[i]-'A'+10)*pow(16,len-i);
        }
        cout << n << endl;
    }
}