The Number of Weak Characters in the Game — LeetCode 1996 Python Solution

The problem

You are playing a game that contains multiple characters, and each of the characters has two main properties: attack and defense. You are given a 2D integer array properties where properties[i] = [attacki, defensei] represents the properties of the ith character in the game.

Example

Input

properties = [[5,5],[6,3],[3,6]]

Output

0

Explanation

No character has strictly greater attack and defense than the other.

Python solution

class Solution:
    def numberOfWeakCharacters(self, properties: List[List[int]]) -> int:
        properties.sort(key=lambda x: (-x[0], x[1]))
        ans = mx = 0
        for _, x in properties:
            ans += x < mx
            mx = max(mx, x)
        return ans

Complexity

Pattern: Stack

When the most recent unresolved thing is the one that matters, use a stack. LeetCode 1996. The Number of Weak Characters in the Game is filed here because LeetCode tags it Stack, which is the vocabulary this hub collects.

The stack guide has the Python template for the pattern and the 194 LeetCode problems that use it.

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