problem1053

README

< Previous 　　　　　　　　　　　　　　　　 Next >

1053. Previous Permutation With One Swap (Medium)

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

 

Example 1:

Input: [3,2,1]
Output: [3,1,2]
Explanation: Swapping 2 and 1.

Example 2:

Input: [1,1,5]
Output: [1,1,5]
Explanation: This is already the smallest permutation.

Example 3:

Input: [1,9,4,6,7]
Output: [1,7,4,6,9]
Explanation: Swapping 9 and 7.

Example 4:

Input: [3,1,1,3]
Output: [1,3,1,3]
Explanation: Swapping 1 and 3.

 

Note:

1. 1 <= A.length <= 10000
2. 1 <= A[i] <= 10000

Related Topics

[Greedy] [Array]

Hints

Hint 1

You need to swap two values, one larger than the other. Where is the larger one located?