Question

1996. The Number of Weak Characters in the Game

中文文档

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

Solution 1

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

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

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

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

function numberOfWeakCharacters(properties: number[][]): number {
  properties.sort((a, b) => (a[0] == b[0] ? a[1] - b[1] : b[0] - a[0]));
  let ans = 0;
  let mx = 0;
  for (const [, x] of properties) {
    if (x < mx) {
      ans++;
    } else {
      mx = x;
    }
  }
  return ans;
}

/**
 * @param {number[][]} properties
 * @return {number}
 */
var numberOfWeakCharacters = function (properties) {
  properties.sort((a, b) => (a[0] == b[0] ? a[1] - b[1] : b[0] - a[0]));
  let ans = 0;
  let mx = 0;
  for (const [, x] of properties) {
    if (x < mx) {
      ans++;
    } else {
      mx = x;
    }
  }
  return ans;
};