[LeetCode] Height Checker

🔍  문제

A school is trying to take an annual photo of all the students. The students are asked to stand in a single file line in non-decreasing order by height. Let this ordering be represented by the integer array expected where expected[i] is the expected height of the ith student in line.

You are given an integer array heights representing the current order that the students are standing in. Each heights[i] is the height of the ith student in line (0-indexed).

Return the number of indices where heights[i] != expected[i].

Input: heights = [1,1,4,2,1,3]
Output: 3
Explanation: 
heights:  [1,1,4,2,1,3]
expected: [1,1,1,2,3,4]
Indices 2, 4, and 5 do not match.

 

🖥  실행

1) Answer

import copy
class Solution:
    def heightChecker(self, heights: List[int]):
        newHeight = copy.copy(heights)
        newHeight.sort()
        n = 0
        
        for i in range(len(heights)):
            if newHeight[i] != heights[i]:
                n += 1
        
        return n

 

2) Better Solution

class Solution:
    def heightChecker(self, heights: List[int]) -> int:
        return sum(h1 != h2 for h1, h2 in zip(heights, sorted(heights)))