1996. The Number of Weak Characters in the Game

https://leetcode.com/problems/the-number-of-weak-characters-in-the-game

Description

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.

A character is said to be weak if any other character has both attack and defense levels strictly greater than this character's attack and defense levels. More formally, a character i is said to be weak if there exists another character j where attackj > attacki and defensej > defensei.

Return the number of weak characters.

Example 1:

**Input:** properties = [[5,5],[6,3],[3,6]]
**Output:** 0
**Explanation:** No character has strictly greater attack and defense than the other.

Example 2:

**Input:** properties = [[2,2],[3,3]]
**Output:** 1
**Explanation:** The first character is weak because the second character has a strictly greater attack and defense.

Example 3:

**Input:** properties = [[1,5],[10,4],[4,3]]
**Output:** 1
**Explanation:** The third character is weak because the second character has a strictly greater attack and defense.

Constraints:

• 2 <= properties.length <= 105

• properties[i].length == 2

• 1 <= attacki, defensei <= 105

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