Merge Ranges | O(nlgn) time due to sorting and O(n) comparison

Author: SteffiKeranJ

Greedy/merge.cpp

@@ -0,0 +1,25 @@
+class Solution {
+public:
+    vector<vector<int>> merge(vector<vector<int>>& intervals) {
+        // sort it -> O(nlgn) time
+        sort(intervals.begin(), intervals.end());
+        vector<vector<int>> res;
+        if(intervals.size() == 0)
+            return res;
+         int f = intervals[0][0];
+        int s = intervals[0][1];
+        for(int i = 0; i < intervals.size(); ++i) {
+            if (intervals[i][0] <= s) {
+                if(intervals[i][1] > s) {
+                    s = intervals[i][1];
+                }
+            } else {
+                res.push_back({f, s});
+                f = intervals[i][0];
+                s= intervals[i][1];
+            }
+        }
+        res.push_back({f,s});
+        return res;
+    }
+};