LeetCode in Kotlin
1996. The Number of Weak Characters in the Game
Medium
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 <= 105properties[i].length == 21 <= attacki, defensei <= 105
Solution
import java.util.Arrays
class Solution {
fun numberOfWeakCharacters(properties: Array<IntArray>): Int {
Arrays.sort(properties) { a: IntArray, b: IntArray -> if (a[0] == b[0]) b[1] - a[1] else a[0] - b[0] }
var max = properties[properties.size - 1][1]
var count = 0
for (i in properties.size - 2 downTo 0) {
if (properties[i][1] < max) {
count++
}
max = Math.max(max, properties[i][1])
}
return count
}
}