Combinations

Problem statement

Given two integers n and k, return all possible combinations of k numbers out of the range [1, n].

You may return the answer in any order.

Example 1:

Input: n = 4, k = 2Output:[  [2,4],  [3,4],  [2,3],  [1,2],  [1,3],  [1,4],]

Example 2:

Input: n = 1, k = 1Output: [[1]]

Constraints:

• 1 <= n <= 20
• 1 <= k <= n

My solution

/**
 * @param {number} n
 * @param {number} k
 * @return {number[][]}
 */
var combine = function(n, k) {
    let temp = [];
    let result = []
    
    function traverse(startIndex) {
        // console.log(JSON.stringify(temp))
        if (temp.length === k) {
            result.push([...temp])
        }
        
        for (let i = startIndex; i <= n; i++) {
            temp.push(i);
            traverse(i + 1);
            temp.pop();
        }
    }
    
    traverse(1)
    
    return result;
};