🔢 Day 18

Author: AkashRajpurohit

README.md

@@ -26,6 +26,7 @@
 1. [Range Sum of BST](https://leetcode.com/explore/challenge/card/november-leetcoding-challenge/566/week-3-november-15th-november-21st/3532/) ➡️ [CPP Solution](Week3/rangeSumBST.cpp)
 2. [Longest Mountain in Array](https://leetcode.com/explore/challenge/card/november-leetcoding-challenge/566/week-3-november-15th-november-21st/3533/) ➡️ [CPP Solution](Week3/longestMountain.cpp)
 3. [Mirror Reflection](https://leetcode.com/explore/challenge/card/november-leetcoding-challenge/566/week-3-november-15th-november-21st/3534/) ➡️ [CPP Solution](Week3/mirrorReflection.cpp)
+4. [Merge Intervals](https://leetcode.com/explore/challenge/card/november-leetcoding-challenge/566/week-3-november-15th-november-21st/3535/) ➡️ [CPP Solution](Week3/merge.cpp)
 
 ## Week 4 🚧
 Coming soon...

Week3/merge.cpp

@@ -0,0 +1,29 @@
+class Solution {
+public:
+    static bool compare(vector<int> I1, vector<int> I2) {
+        return I1[0] == I2[0] ? I1[1] < I2[1] : I1[0] < I2[0];
+    }
+    vector<vector<int>> merge(vector<vector<int>>& intervals) {
+        int n = intervals.size();
+        if(n == 1) return intervals;
+        
+        vector<vector<int>> res;
+        sort(intervals.begin(), intervals.end(), compare);
+        
+        int i = 0;
+        res.push_back(intervals[i]);
+        
+        for(int j = 1; j < n; ++j) {
+            vector<int>& interval = res.at(i);
+            
+            if(intervals[j][0] <= interval[1]) {
+                interval[1] = max(intervals[j][1], interval[1]);
+            } else {
+                res.push_back(intervals[j]);
+                i++;
+            }
+        }
+        
+        return res;
+    }
+};