From 3358ff24bba8addb7ff4980a1028f4248e753f3d Mon Sep 17 00:00:00 2001
From: Napri <manishhh821@gmail.com>
Date: Tue, 4 Oct 2022 15:06:39 +0530
Subject: [PATCH 1/2] 3Sum Leetcode(15)

---
 Medium/15.3Sum.cpp | 42 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)
 create mode 100644 Medium/15.3Sum.cpp

diff --git a/Medium/15.3Sum.cpp b/Medium/15.3Sum.cpp
new file mode 100644
index 0000000..d5a7432
--- /dev/null
+++ b/Medium/15.3Sum.cpp
@@ -0,0 +1,42 @@
+/* Leetcode Problem: 15. 3Sum
+   Link: https://leetcode.com/problems/3sum/
+*/
+
+
+class Solution {
+public:
+    vector<vector<int>> threeSum(vector<int>& nums) {
+        int n = nums.size();
+        sort(nums.begin(), nums.end());
+        
+        vector<vector<int>> ans;
+        for(int i=0; i<n-2; i++)
+        {            
+            // for removing duplicates in the first element
+            if(i > 0 && nums[i] == nums[i-1])continue;
+                int a = i+1, b = n-1;
+                while(a < b)
+                {
+                    int sum = nums[i]+nums[a]+nums[b];
+                    // cout<<sum<<" ";
+                    if(sum == 0)
+                    {
+                        ans.push_back({nums[i],nums[a],nums[b]});
+                        // for removing duplicates in the second element
+                        while(a < b && nums[a] == nums[a+1])
+                            a++;
+                        // for removing duplicates in the third element
+                        while(a < b && nums[b] == nums[b-1])
+                            b--;
+                        a++;
+                        b--;
+                    }
+                    else if(sum > 0)
+                        b--;
+                    else
+                        a++;
+                }
+        }
+        return ans;
+    }
+};
\ No newline at end of file

From fca922fd7e1b61f2864e805150298aaf8b657f44 Mon Sep 17 00:00:00 2001
From: Napri <manishhh821@gmail.com>
Date: Tue, 4 Oct 2022 18:42:03 +0530
Subject: [PATCH 2/2] Added Leetcode(56)

---
 Medium/15.3Sum.cpp            | 42 ------------------------------
 Medium/56.Merge_Intervals.cpp | 48 +++++++++++++++++++++++++++++++++++
 2 files changed, 48 insertions(+), 42 deletions(-)
 delete mode 100644 Medium/15.3Sum.cpp
 create mode 100644 Medium/56.Merge_Intervals.cpp

diff --git a/Medium/15.3Sum.cpp b/Medium/15.3Sum.cpp
deleted file mode 100644
index d5a7432..0000000
--- a/Medium/15.3Sum.cpp
+++ /dev/null
@@ -1,42 +0,0 @@
-/* Leetcode Problem: 15. 3Sum
-   Link: https://leetcode.com/problems/3sum/
-*/
-
-
-class Solution {
-public:
-    vector<vector<int>> threeSum(vector<int>& nums) {
-        int n = nums.size();
-        sort(nums.begin(), nums.end());
-        
-        vector<vector<int>> ans;
-        for(int i=0; i<n-2; i++)
-        {            
-            // for removing duplicates in the first element
-            if(i > 0 && nums[i] == nums[i-1])continue;
-                int a = i+1, b = n-1;
-                while(a < b)
-                {
-                    int sum = nums[i]+nums[a]+nums[b];
-                    // cout<<sum<<" ";
-                    if(sum == 0)
-                    {
-                        ans.push_back({nums[i],nums[a],nums[b]});
-                        // for removing duplicates in the second element
-                        while(a < b && nums[a] == nums[a+1])
-                            a++;
-                        // for removing duplicates in the third element
-                        while(a < b && nums[b] == nums[b-1])
-                            b--;
-                        a++;
-                        b--;
-                    }
-                    else if(sum > 0)
-                        b--;
-                    else
-                        a++;
-                }
-        }
-        return ans;
-    }
-};
\ No newline at end of file
diff --git a/Medium/56.Merge_Intervals.cpp b/Medium/56.Merge_Intervals.cpp
new file mode 100644
index 0000000..f6b701a
--- /dev/null
+++ b/Medium/56.Merge_Intervals.cpp
@@ -0,0 +1,48 @@
+/*
+Given an array of intervals where intervals[i] = [starti, endi], merge all overlapping intervals,
+ and return an array of the non-overlapping intervals that cover all the intervals in the input.
+
+Example 1:
+Input: intervals = [[1,3],[2,6],[8,10],[15,18]]
+Output: [[1,6],[8,10],[15,18]]
+
+1----3                      => 1----6
+  2----6
+        8----10             => 8----10  
+                15----18    => 15----18
+
+*/
+
+
+class Solution {
+public:
+    vector<vector<int>> merge(vector<vector<int>>& intervals) {
+        
+        vector<vector<int>> ans;
+        sort(intervals.begin(), intervals.end());
+        
+        int n = intervals.size();
+        for(int i=0; i<n; i++)
+        {
+            int s1 = intervals[i][0], e1 = intervals[i][1];
+            for(int j=i+1; j<n; j++)
+            {
+                int s2 = intervals[j][0], e2 = intervals[j][1];
+                // if overlap
+                if(s2 <= e1){
+                    e1 = max(e1, e2);
+                    i = j;
+                }
+                // else break out of inner loop and add to ans
+                else
+                {
+                    i=j-1;
+                    break;
+                }
+            }
+            ans.push_back({s1, e1});
+        }   
+        
+        return ans;
+    }
+};
\ No newline at end of file