100%AC原生代码

A30850.【进制转换】正整数的任意进制转换

#include <bits/stdc++.h>
using namespace std;
int c2v[128] = {0};
char v2c[36] = {0};
void init() {
    for (int i = 0; i < 10; ++i) {
        c2v['0' + i] = i;
        v2c[i] = '0' + i;
    }
    for (int i = 0; i < 26; ++i) {
        c2v['A' + i] = 10 + i;
        v2c[10 + i] = 'A' + i;
    }
}
unsigned long long p2d(const string &s, int p) {
    unsigned long long r = 0;
    for (char c : s) r = r * p + c2v[c];
    return r;
}
string d2q(unsigned long long n, int q) {
    if (!n) return "0";
    string r;
    while (n) {
        r += v2c[n % q];
        n /= q;
    }
    reverse(r.begin(), r.end());
    return r;
}
int main() {
    init(); 
    int m;
    cin >> m;
    cin.ignore();
    while (m--) {
        string l;
        getline(cin, l);
        int p = stoi(l.substr(0, l.find(',')));
        string s = l.substr(l.find(',') + 1, l.rfind(',') - l.find(',') - 1);
        int q = stoi(l.substr(l.rfind(',') + 1));
        cout << d2q(p2d(s, p), q) << endl;
    }
    return 0;
}