Recursion: Given a decimal number, convert into binary number using recursion

Problem Statement:

Given a decimal number, convert into binary number using recursion

Example:

Input:

n = 7
Output: 111

Solution Explanation:

In this approach, we recursively divide the decimal number by 2 and append the remainder as the next binary digit.

Constructing the binary representation from right to left

Time Complexity: O(log2n)
Space Complexity: O(log2n)

Code Solution

#include <iostream>
#include <cmath>
using namespace std;

int solution(int num)
{
	//base case
    if (num == 0) 
        return 0; 
    else
        return (num % 2 + 10 * solution(num / 2));
}

int main()
{
    int num = 7;
    cout << solution(num);
    return 0;
}

Output

111