Time: 2143 ms (5.01%), Space: 291.6 MB (7.08%) - LeetHub

0015-3sum/0015-3sum.cpp

@@ -1,35 +1,38 @@
 class Solution {
 public:
     vector<vector<int>> threeSum(vector<int>& nums) {
-        vector<vector<int>> res;
-        int n = nums.size();
-
-        if(nums.size() < 3)
-            return res;
-
+        set<vector<int>> res;
         sort(begin(nums), end(nums));
 
-        for(int i = 0; i < nums.size(); i++){
-            int t = nums[i], l = i + 1, r = nums.size() - 1;
+        for(int i = 0; i < nums.size(); i++) {
+            int temp = nums[i];
+            int l = 0, r = nums.size() - 1;
 
-            while(l < r){
-                int sum = t + nums[l] + nums[r];
-                if(sum == 0){
-                    res.push_back({t, nums[l], nums[r]});
-                    while(l <r && nums[l] == nums[l + 1]) l++;
-                    while(l < r && nums[r] == nums[r - 1]) r--;
-
+            while(l < r) {
+                int sum = nums[l] + nums[r] + temp;
+                // cout<<<<temp<<" "<<nums[l]sum<<endl;
+                if(sum == 0 && l != i && r != i) {
+                    vector<int> temp_v = {nums[l], nums[r], temp};
+                    sort(begin(temp_v), end(temp_v));
+                    res.insert(temp_v);
                     l++;
                     r--;
-                }else if(sum > 0){
-                    r--;
-                }else{
+                } else if(sum < 0) {
                     l++;
+                } else if (sum > 0) {
+                    r--;
+                } else if(l == i || r == i) {
+                    break;
                 }
             }
-            while(i + 1 < n && nums[i] == nums[i + 1]) i++;
         }
 
-        return res;
+        vector<vector<int>> res_v;
+
+        for(vector<int> v: res) {
+            res_v.push_back(v);
+        }
+
+        return res_v;
     }
 };