@@ -9,27 +9,25 @@ import TwoPointersTopic
99 * 287. Find the Duplicate Number
1010 * https://leetcode.com/problems/find-the-duplicate-number/
1111 *
12- * Given an array of integers nums containing n + 1 integers where each integer is in the range [1, n] inclusive.
13-
12+ Given an array of integers nums containing n + 1 integers where each integer is in the range [1, n] inclusive.
1413There is only one repeated number in nums, return this repeated number.
15-
1614You must solve the problem without modifying the array nums and uses only constant extra space.
1715 */
1816
1917class Medium287 : ArraysTopic , TwoPointersTopic , BinaryTreeTopic , BitManipulationTopic {
2018
2119 fun findDuplicate (nums : IntArray ): Int {
22- if (nums.size == 1 ) {
23- return nums[0 ]
24- }
25- val map = HashMap <Int ,Int >()
20+ if (nums.size == 1 ) return nums.first()
21+ val map = HashMap <Int , Boolean >()
2622 nums.forEach {
27- if (map.getOrDefault(it, 0 ) == 1 ) {
28- return it
29- } else {
30- map.set(it, 1 )
31- }
23+ if (map[it] == true ) return it
24+ map[it] = true
3225 }
3326 return 0
3427 }
28+ }
29+ 30+ fun main () {
31+ println (Medium287 ().findDuplicate(intArrayOf(1 , 3 , 4 , 2 , 2 )))
32+ println (Medium287 ().findDuplicate(intArrayOf(3 , 1 , 3 , 4 , 2 )))
3533}
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