Medium881 challenge

Author: konstantin

src/medium/881. Boats to Save People .kt

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+package medium
+
+import ArraysTopic
+import GreedyTopic
+import SortingTopic
+import TwoPointersTopic
+
+/**
+ * 881. Boats to Save People
+ * https://leetcode.com/problems/boats-to-save-people/
+ *
+You are given an array people where people[i] is the weight of the ith person,
+and an infinite number of boats where each boat can carry a maximum weight of limit.
+Each boat carries at most two people at the same time, provided the sum of the weight of those people is at most limit.
+Return the minimum number of boats to carry every given person.
+ */
+
+class Medium881 : ArraysTopic, TwoPointersTopic, GreedyTopic, SortingTopic {
+
+    fun numRescueBoats(people: IntArray, limit: Int): Int {
+        people.sort()
+        var result = 0
+        for (i in people.indices) {
+            if (people[i] == 0) continue
+            for (j in people.lastIndex downTo i + 1) {
+                if (people[j] == 0) continue
+                if (people[j] + people[i] > limit) continue
+                people[j] = 0
+                break
+            }
+            people[i] = 0
+            result++
+        }
+        return result
+    }
+}
+
+fun main() {
+    println(Medium881().numRescueBoats(intArrayOf(1, 2), 3))
+    println(Medium881().numRescueBoats(intArrayOf(3, 2, 2, 1), 3))
+    println(Medium881().numRescueBoats(intArrayOf(3, 5, 3, 4), 5))
+    println(Medium881().numRescueBoats(intArrayOf(5, 1, 4, 2), 6))
+}