java.lang.Object
g1001_1100.s1053_previous_permutation_with_one_swap.Solution

public class Solution extends Object
1053 - Previous Permutation With One Swap.

Medium

Given an array of positive integers arr (not necessarily distinct), return the lexicographically largest permutation that is smaller than arr, that can be made with exactly one swap (A swap exchanges the positions of two numbers arr[i] and arr[j]). If it cannot be done, then return the same array.

Example 1:

Input: arr = [3,2,1]

Output: [3,1,2]

Explanation: Swapping 2 and 1.

Example 2:

Input: arr = [1,1,5]

Output: [1,1,5]

Explanation: This is already the smallest permutation.

Example 3:

Input: arr = [1,9,4,6,7]

Output: [1,7,4,6,9]

Explanation: Swapping 9 and 7.

Constraints:

  • 1 <= arr.length <= 104
  • 1 <= arr[i] <= 104
  • Constructor Details Link icon

    • Solution Link icon

      public Solution()
  • Method Details Link icon

    • prevPermOpt1 Link icon

      public int[] prevPermOpt1(int[] arr)