Leetcode - Replace Elements with Greatest Element on Right Side Solution
Poor Man
- Published
- Updated
- Reading time
- 2 min read
- Length
- 207 words
Given an array arr, replace every element in that array with the greatest element among the elements to its right, and replace the last element with -1.
After doing so, return the array.
Example 1:
Text
Input: arr = [17,18,5,4,6,1]
Output: [18,6,6,6,1,-1]
Explanation:
- index 0 --> the greatest element to the right of index 0 is index 1 (18).
- index 1 --> the greatest element to the right of index 1 is index 4 (6).
- index 2 --> the greatest element to the right of index 2 is index 4 (6).
- index 3 --> the greatest element to the right of index 3 is index 4 (6).
- index 4 --> the greatest element to the right of index 4 is index 5 (1).
- index 5 --> there are no elements to the right of index 5, so we put -1.Example 2:
Text
Input: arr = [400]
Output: [-1]
Explanation: There are no elements to the right of index 0.Constraints:
1 <= arr.length <= 1041 <= arr[i] <= 105
Solution in Python#
Python
from collections import deque
class Solution:
def replaceElements(self, arr: List[int]) -> List[int]:
max_val = 0
max_arr = deque([-1])
for i in arr[:0:-1]:
max_val = max(max_val,i)
max_arr.appendleft(max_val)
return list(max_arr)