README_EN.md

1996. The Number of Weak Characters in the Game

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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

Solutions

Python3

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

Java

class Solution {
    public int numberOfWeakCharacters(int[][] properties) {
        Arrays.sort(properties, (a, b) -> { return a[0] == b[0] ? a[1] - b[1] : b[0] - a[0]; });
        int ans = 0, mx = 0;
        for (int[] p : properties) {
            if (mx > p[1]) {
                ++ans;
            }
            mx = Math.max(mx, p[1]);
        }
        return ans;
    }
}

TypeScript

function numberOfWeakCharacters(properties: number[][]): number {
    properties.sort((a, b) => (a[0] != b[0] ? b[0] - a[0] : a[1] - b[1]));

    let ans = 0;
    let max = 0;
    for (let [, b] of properties) {
        if (b < max) {
            ans++;
        } else {
            max = b;
        }
    }
    return ans;
}

C++

class Solution {
public:
    int numberOfWeakCharacters(vector<vector<int>>& properties) {
        sort(properties.begin(), properties.end(), [&](vector<int>& a, vector<int>& b) { return a[0] == b[0] ? a[1] < b[1] : a[0] > b[0]; });
        int ans = 0, mx = 0;
        for (auto& p : properties) {
            if (mx > p[1])
                ++ans;
            else
                mx = p[1];
        }
        return ans;
    }
};

Go

func numberOfWeakCharacters(properties [][]int) int {
	sort.Slice(properties, func(i, j int) bool {
		if properties[i][0] == properties[j][0] {
			return properties[i][1] < properties[j][1]
		}
		return properties[i][0] > properties[j][0]
	})
	ans, mx := 0, 0
	for _, p := range properties {
		if mx > p[1] {
			ans++
		} else {
			mx = p[1]
		}
	}
	return ans
}

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