[LeetCode]#1299. Replace Elements with Greatest Element on Right Side

Environment: Python 3.7

Key technique: append

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:

Input: arr = [17,18,5,4,6,1]
Output: [18,6,6,6,1,-1]

Constraints:

  • 1 <= arr.length <= 10^4
  • 1 <= arr[i] <= 10^5

Analysis:

As below, find right side maximum number and add it to ans list. We can get answer when the searching list is finish.

Solution:

class Solution:
def replaceElements(self, arr):
l=len(arr)
ans=[]
for i in range(l-1):

arr_r=max(arr[i+1:])
ans.append(arr_r)
ans.append(-1)
return ans

Submitted result:

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