Merge remote-tracking branch 'origin/master'

Author: konstantin

src/medium/287. Find the Duplicate Number .kt

@@ -9,27 +9,25 @@ import TwoPointersTopic
  * 287. Find the Duplicate Number
  * https://leetcode.com/problems/find-the-duplicate-number/
  *
- * Given an array of integers nums containing n + 1 integers where each integer is in the range [1, n] inclusive.
-
+Given an array of integers nums containing n + 1 integers where each integer is in the range [1, n] inclusive.
 There is only one repeated number in nums, return this repeated number.
-
 You must solve the problem without modifying the array nums and uses only constant extra space.
  */
 
 class Medium287 : ArraysTopic, TwoPointersTopic, BinaryTreeTopic, BitManipulationTopic {
 
     fun findDuplicate(nums: IntArray): Int {
-        if (nums.size == 1) {
-            return nums[0]
-        }
-        val map = HashMap<Int,Int>()
+        if (nums.size == 1) return nums.first()
+        val map = HashMap<Int, Boolean>()
         nums.forEach {
-            if (map.getOrDefault(it, 0) == 1) {
-                return it
-            } else {
-                map.set(it, 1)
-            }
+            if (map[it] == true) return it
+            map[it] = true
         }
         return 0
     }
+}
+
+fun main() {
+    println(Medium287().findDuplicate(intArrayOf(1, 3, 4, 2, 2)))
+    println(Medium287().findDuplicate(intArrayOf(3, 1, 3, 4, 2)))
 }