"""
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

hint:
1 Sort the array on the basis of the attack values and group characters with the same attack together. How can you use these groups?
2 Characters in one group will always have a lesser attack value than the characters of the next group. Hence, we will only need to check if there is a higher defense value present in the next groups.
"""
from typing import List


class TheNumberOfWeakCharactersInTheGame:
    def numberOfWeakCharacters(self, properties: List[List[int]]) -> int:
        properties.sort(key= lambda x: (-x[0], x[1]))
        res = max_defense = 0
        for _, defense in properties:
            if defense < max_defense:
                res += 1
            else:
                max_defense = defense
        return res
