Time: 26 ms (51.16%), Space: 42.4 MB (95.08%) - LeetHub

Author: monishasuthapalli

3sum/3sum.java

@@ -0,0 +1,44 @@
+class Solution {
+    
+    
+    public List<List<Integer>> threeSum(int[] nums) {
+        Arrays.sort(nums);
+        List<List<Integer>> triplets=new ArrayList<>();
+        for(int i=0;i<nums.length-2;i++)
+        {
+            if(i>0&&nums[i]==nums[i-1])
+                continue;
+            searchTriplet(nums,-nums[i],i+1,triplets);
+        }
+        
+        return triplets;
+    }
+    
+    public static void searchTriplet(int[] arr,int target,int left,List<List<Integer>> triplets)
+    {
+        int right=arr.length-1;
+        while(left<right)
+        {
+            int currSum=arr[left]+arr[right];
+            if(currSum==target)
+            {
+                triplets.add(Arrays.asList(-target,arr[left],arr[right]));
+                left++;
+                right--;
+                
+                
+                while(left<right&&arr[left]==arr[left-1])
+                    left++;
+                while(left<right&&arr[right]==arr[right+1])
+                    right--;
+            }
+            
+            else if(target>currSum)
+                left++;
+            else
+                right--;
+            
+        }
+        
+    }
+}