C++用短除法把十进制转换为二进制输出

#include <iostream>
#include <Windows.h>
#include <string>
using namespace std;
int main() {
    int n;
    int ret[32];
    int i = 0;

    cout << "请输入一个正整数：";
    cin >> n;

    if (n < 0) {
        cout << "需要输入一个正整数!" << endl;
        system("pause");
        return 1;
    }

    while (n != 0) {
        ret[i] = n % 2;
        n = n / 2;
        i++;
    }

    for (i--; i >= 0; i--) {
        cout << ret[i] ;
    }
    cout << endl;
    system("pause");
    return 0;
}

 进化版：

#include <iostream>
#include <string>
#include <windows.h>
using namespace std;
int main() {
    int n;
    int ret[32];
    int i = 0;

    while (1){
        system("cls"); //清除屏幕
        cout << "请输入一个正整数：";
        cin >> n;
        if (n > 0) {
            break;
        }
        else {
            cout << "需要输入一个正整数!" << endl;
            system("pause");
        }
    }

    while (n != 0) {
        ret[i] = n % 2;
        n = n / 2;
        i++;
    }

    for (i--; i >= 0; i--) {
        cout << ret[i];
    }
    cout << endl;
    system("pause");
    return 0;
}