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Generate Binary Numbers

Tags : queue, geeksforgeeks, cpp, easy

Problem Statement - link #

Given a number N. The task is to generate and print all binary numbers with decimal values from 1 to N.

Your Task: You only need to complete the function generate() that takes N as parameter and returns vector of strings denoting binary numbers.

Expected Time Complexity: O(N logN)
Expected Auxiliary Space: O(N logN)

Examples #

Example 1:

Input:
N = 5
Output: 
1 10 11 100 101
Explanation: 
Binary numbers from
1 to 5 are 1 , 10 , 11 , 100 and 101.

Example 2:

Input:
N = 2
Output: 
1 10
Explanation: 
Binary numbers from
1 to 2 are 1 and 10.

Constraints #

Solutions #

//Function to generate binary numbers from 1 to N using a queue.
vector<string> generate(int N)
{
	// Your code here
	queue<string> q;
	q.push("1");
	vector<string> v;
	while(N--){
	    string s = q.front(); q.pop();
	    q.push(s+"0");
	    q.push(s+"1");
	    v.push_back(s);
	}
	return v;
}