3sum solution

Author: PDKhan

3sum/PDKhan.cpp

@@ -0,0 +1,36 @@
+class Solution {
+    public:
+        vector<vector<int>> threeSum(vector<int>& nums) {
+            vector<vector<int>> result;
+            sort(nums.begin(), nums.end());
+    
+            for(int i = 0; i < nums.size(); i++){
+                if(i > 0 && nums[i] == nums[i-1])
+                    continue;
+                
+                int left = i + 1;
+                int right = nums.size() - 1;
+    
+                while(left < right){
+                    int sum = nums[i] + nums[left] + nums[right];
+    
+                    if(sum == 0){
+                        result.push_back({nums[i], nums[left], nums[right]});
+                        left++;
+                        right--;
+    
+                        while(left < right && nums[left] == nums[left-1])
+                            left++;
+                    
+                        while(left < right && nums[right] == nums[right+1])
+                            right--;
+                    }else if(sum < 0)
+                        left++;
+                    else
+                        right--;
+                }
+            }
+    
+            return result;
+        }
+    };