From 9c470bd0554bab9fcee25a92da4faa1619e6b426 Mon Sep 17 00:00:00 2001
From: SquidSpirit <squid@squidspirit.com>
Date: Wed, 19 Feb 2025 00:50:15 +0800
Subject: [PATCH] feat: 15_3sum

---
 15_3sum/main.cpp | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)
 create mode 100644 15_3sum/main.cpp

diff --git a/15_3sum/main.cpp b/15_3sum/main.cpp
new file mode 100644
index 0000000..d31ee0b
--- /dev/null
+++ b/15_3sum/main.cpp
@@ -0,0 +1,33 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+class Solution {
+   public:
+    vector<vector<int>> threeSum(vector<int> &nums) {
+        set<vector<int>> st;
+
+        sort(nums.begin(), nums.end());
+
+        for (int i = 0; i < nums.size(); i++) {
+            int target = -nums[i];
+            int l = i + 1, r = nums.size() - 1;
+
+            while (l < r) {
+                if (nums[l] + nums[r] < target) {
+                    l++;
+                } else if (nums[l] + nums[r] > target) {
+                    r--;
+                } else {
+                    st.insert({nums[i], nums[l], nums[r]});
+                    l++;
+                }
+            }
+        }
+
+        vector<vector<int>> result;
+        for (auto &v : st) {
+            result.push_back(v);
+        }
+        return result;
+    }
+};