3sum solution

Author: yhkee0404

3sum/yhkee0404.kt

@@ -0,0 +1,31 @@
+class Solution {
+    fun threeSum(nums: IntArray): List<List<Int>> {
+        val ans = mutableListOf<List<Int>>()
+        nums.sort()
+        for (i in 0 until nums.size) {
+            if (i != 0 && nums[i] == nums[i - 1]) {
+                continue
+            }
+            var j = i + 1
+            var k = nums.size - 1
+            while (j < k) {
+                if (j != i + 1 && nums[j] == nums[j - 1]) {
+                    j++
+                    continue
+                }
+                val u = nums[i] + nums[j]
+                while (j < k && u > - nums[k]) {
+                    k--
+                }
+                if (j >= k) {
+                    break
+                }
+                if (u == - nums[k]) {
+                    ans.add(listOf(nums[i], nums[j], nums[k]))
+                }
+                j++
+            }
+        }
+        return ans
+    }
+}