Add longest consecutive sequence solution

Author: hyunjung-choi

longest-consecutive-sequence/hyunjung-choi.kt

@@ -0,0 +1,24 @@
+package leetcode_study
+
+class Solution {
+    fun longestConsecutive(nums: IntArray): Int {
+        if (nums.isEmpty()) return 0
+
+        val sortedNums = nums.sorted()
+        var maxLength = 1
+        var currentLength = 1
+
+        for (i in 1 until sortedNums.size) {
+            when {
+                sortedNums[i] == sortedNums[i - 1] -> continue
+                sortedNums[i] == sortedNums[i - 1] + 1 -> {
+                    currentLength++
+                    maxLength = maxOf(maxLength, currentLength)
+                }
+                else -> currentLength = 1
+            }
+        }
+
+        return maxLength
+    }
+}