[알고리즘] 진법 변환

#include<iostream>
#include<vector>
#include<algorithm>
#include <cmath>
 
using namespace std;
 
int main()
{
 
    string n;
    long long m;
    long long ans = 0;
    int cnt = 0;
    cin >> n ;
    cin >> m ;
 
    for(int i = n.length()-1 ; i != -1 ; i--)
    {
        int tmp = 0;
 
        if(n[i] - '0' < 10) tmp = n[i] - '0';
        else tmp = (n[i] - 'A') + 10;
 
        ans += pow(m, cnt) * tmp;
        cnt++;
    }
 
    cout << ans << endl;
 
 
}