#15

Author: aayush26

#15/java/Solution.java

@@ -0,0 +1,34 @@
+/**
+* https://leetcode.com/problems/3sum/
+* Your runtime beats 33.97 % of java submissions.
+* Your memory usage beats 24.76 % of java submissions.
+*/
+class Solution {
+    public List<List<Integer>> threeSum(int[] nums) {
+        List<List<Integer>> ll = new LinkedList<>();
+        if(nums.length<3) return ll;
+        Arrays.sort(nums);
+        Set<Pair<Integer, Integer>> s = new HashSet<>();
+        for(int i=0; i<nums.length-2; i++){
+            int j=i+1, k=nums.length-1;
+            while(j<k){
+                int sum = nums[i]+nums[j]+nums[k];
+                if(sum==0){
+                    int min = Math.min(nums[i], Math.min(nums[j], nums[k]));
+                    int max = Math.max(nums[i], Math.max(nums[j], nums[k]));
+                    if(s.add(new Pair<Integer, Integer>(min, max))){
+                        List<Integer> l = new LinkedList<>();
+                        l.add(nums[i]);
+                        l.add(nums[j]);
+                        l.add(nums[k]);
+                        ll.add(l);
+                    }
+                    j++;
+                    k--;
+                } else if(sum<0) j++;
+                else k--;
+            }
+        }
+        return ll;
+    }
+}