题解 | #进制转换#

//土尔逊Torson 编写于2023/5/03
#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <cstdio>
#include <string>
#include <vector>

using namespace std;

string Divide(string str, int x) { //字符串除法
	int remainder = 0;             //保存余数
	for (int i = 0; i < str.size(); ++i) {
		int current = remainder * 10 + str[i] - '0';
		str[i] = current / x + '0';
		remainder = current % x;
	}
	int pos = 0;
	while (str[pos] == '0') {       //寻找首个非0下标
		pos++;
	}
	return str.substr(pos);         //删除前置多余的0
}

int main() {
	string str;
	while (cin >> str) {
		vector<int> binary;
		while (str.size() != 0) {
			int last = str[str.size() - 1] - '0'; //最低位的值
			binary.push_back(last % 2);           //取模运算
			str = Divide(str, 2);                 //整除运算
		}
		for (int i = binary.size() - 1; i >= 0; --i) {
			printf("%d", binary[i]);
		}
		printf("\n");
	}
	system("pause");
	return EXIT_SUCCESS;
}
// 64 位输出请用 printf("%lld")