题解 | #进制转换2#

//土尔逊Torson 编写于2023/5/04
#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <cstdio>
#include <string>
#include <vector>

using namespace std;

char IntToChar(int x) {      //数字转字符
	if (x < 10) {
		return x + '0';
	}
	else {
		return x - 10 + 'a';
	}
}

int CharToInt(char c) {      //字符转数字
	if (c >= '0' && c <= '9') {
		return c - '0';
	}
	else {
		return c - 'A' + 10;
	}
}

int main() {
	int m, n;
	scanf("%d%d", &m, &n);
	string str;
	cin >> str;
	long long number = 0;
	for (int i = 0; i < str.size(); ++i) {        //m进制转十进制
		number *= m;
		number += CharToInt(str[i]);
	}
	vector<char> answer;
	while (number != 0) {                         //十进制转n进制
		answer.push_back(IntToChar(number % n));
		number /= n;
	}
	for (int i = answer.size() - 1; i >= 0; --i) { //逆序输出
		printf("%c", answer[i]);
	}
	printf("\n");
	system("pause");
	return EXIT_SUCCESS;
}
// 64 位输出请用 printf("%lld")