LeetcodeMay 12, 2025

Permutations

Hazrat Ali

Leetcode

Given an array nums of distinct integers, return all the possible permutation. You can return the answer in any order.

 

Example 1:

Input: nums = [1,2,3]
Output: [[1,2,3],[1,3,2],[2,1,3],[2,3,1],[3,1,2],[3,2,1]]

Example 2:

Input: nums = [0,1]
Output: [[0,1],[1,0]]

Example 3:

Input: nums = [1]
Output: [[1]]


Solution
/**
 * @param {number[]} nums
 * @return {number[][]}
 */
const permute = nums => {
  const results = [];
  backtracking(nums, {}, [], results);
  return results;
};

const backtracking = (nums, used, solution, results) => {
  if (solution.length === nums.length) {
    results.push(solution.slice());
    return;
  }

  for (let i = 0; i < nums.length; i++) {
    if (used[i]) {
      continue;
    }

    solution.push(nums[i]);
    used[i] = true;
    backtracking(nums, used, solution, results);
    solution.pop();
    used[i] = false;
  }
}








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