From 6b470e61fb4b89c370e594ea97285aef08ecc976 Mon Sep 17 00:00:00 2001
From: Vimal Anand <78069624+Vimal2023@users.noreply.github.com>
Date: Wed, 18 Oct 2023 20:27:21 +0530
Subject: [PATCH] Create 3sum-leetcode.cpp

Given an integer array nums, return all the triplets [nums[i], nums[j], nums[k]] such that i != j, i != k, and j != k, and nums[i] + nums[j] + nums[k] == 0.
---
 03-Arrays/3sum-leetcode.cpp | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)
 create mode 100644 03-Arrays/3sum-leetcode.cpp

diff --git a/03-Arrays/3sum-leetcode.cpp b/03-Arrays/3sum-leetcode.cpp
new file mode 100644
index 0000000..3cc3ff6
--- /dev/null
+++ b/03-Arrays/3sum-leetcode.cpp
@@ -0,0 +1,29 @@
+//Optimized Approach - O(n^2 logn + nlogn) - o(n^2 logn) time and O(n) space
+class Solution {
+public:
+    vector<vector<int>> threeSum(vector<int>& nums) {
+        int target = 0;
+        sort(nums.begin(), nums.end());
+        set<vector<int>> s;
+        vector<vector<int>> output;
+        for (int i = 0; i < nums.size(); i++){
+            int j = i + 1;
+            int k = nums.size() - 1;
+            while (j < k) {
+                int sum = nums[i] + nums[j] + nums[k];
+                if (sum == target) {
+                    s.insert({nums[i], nums[j], nums[k]});
+                    j++;
+                    k--;
+                } else if (sum < target) {
+                    j++;
+                } else {
+                    k--;
+                }
+            }
+        }
+        for(auto triplets : s)
+            output.push_back(triplets);
+        return output;
+    }
+};