题解 | #进制转换2#

#define _CRT_SECURE_NO_WARNINGS 1
#include <bits/stdc++.h>
using namespace std;
int charToint(char C) {
    int k = 0;
    if (C >= '0' && C <= '9')k = C - '0';
    else k = C - 'A' + 10;
    return k;
}

char intTochar(int x) {
    char c = ' ';
    if (x < 10)c = x + '0';
    else c = x - 10 + 'A';
    return c;
}
int main() {
    int m = 0, n = 0;
    scanf("%d%d", &m, &n);
    string str;
    cin >> str;
    long long number = 0;
    vector<char>ansever;
    for (int i = 0; i < str.size(); i++) {
        number = number * m;
        number = number + charToint(str[i]);
    }
    while (number != 0) {
        ansever.push_back(intTochar(number % n));
        number = number / n;
    }
    for (int i = ansever.size() - 1; i >= 0; i--) {
        cout << ansever[i];
    }
    cout << endl;
    return 0;
}