How do you solve Sort the People on LeetCode?

Sort the People (LeetCode #2418) can be solved using Brute Force or Optimal Solution. The optimal approach is Optimal Solution with O(n log n) time complexity and O(n) space complexity. Key insight: Sorting can drastically reduce the complexity of the problem compared to finding maximums repeatedly.

What is the time complexity of Sort the People?

The optimal solution for Sort the People runs in O(n log n) time and uses O(n) space. This complexity is due to the sorting step, which is more efficient than the nested loops used in the brute-force approach.

What is the brute force solution for Sort the People?

The brute force approach for Sort the People is Brute Force, with O(n²) time complexity and O(1) space complexity. The brute-force approach involves repeatedly finding the tallest person and placing them in the correct position. This is akin to sorting a deck of cards by repeatedly finding the highest card and moving it to the front. The optimal Optimal Solution approach improves this to O(n log n).

What algorithm or data structure is used to solve Sort the People?

Sort the People uses the following concepts: Array, Hash Table, String, Sorting. The recommended patterns to study are: Sorting, Array.

What are the interview tips for Sort the People?

Always clarify the problem requirements and constraints before jumping into coding. Think about the efficiency of your approach and be prepared to discuss trade-offs. Practice explaining your thought process as you code, as this can help you catch mistakes early.

What are common mistakes when solving Sort the People?

Not considering the need to maintain the association between names and heights when sorting. Overlooking the fact that heights are distinct, which simplifies the sorting process.

#2418

Sort the People

Easy

ArrayHash TableStringSortingSortingArray

LeetCode ↗

Approaches

Brute ForceOptimal

Complexity Comparison

	Brute Force	Optimal Solution★
Time	O(n²)	O(n log n)
Space	O(1)	O(n)

💡

Intuition

Time O(n log n)Space O(n)

The optimal solution leverages sorting to efficiently arrange names based on heights. This is like organizing a list of books by height using a library's sorting system.

⚙️

Algorithm

3 steps

1Step 1: Create a list of tuples pairing each name with its corresponding height.
2Step 2: Sort this list of tuples based on the height in descending order.
3Step 3: Extract the names from the sorted list and return them.

solution.py4 lines

1def sortPeople(names, heights):
2    people = list(zip(heights, names))
3    people.sort(reverse=True)
4    return [name for height, name in people]

ℹ

Complexity note: This complexity is due to the sorting step, which is more efficient than the nested loops used in the brute-force approach.

1Sorting can drastically reduce the complexity of the problem compared to finding maximums repeatedly.
2Using data structures like tuples or pairs can simplify the association between names and heights.

Solutions and explanations are original Tejav content. Problem titles © LeetCode — use the LeetCode button above for the full problem statement.