Create merge_intervals.cpp

Author: avidLearnerInProgress

merge_intervals.cpp

@@ -0,0 +1,40 @@
+class Solution {
+public:
+    vector<vector<int>> merge(vector<vector<int>>& intervals) {
+        
+        if(intervals.size() == 0) return vector<vector<int>>();
+        vector<vector<int>> result;   
+        sort(intervals.begin(), intervals.end(), [](vector<int> &a, vector<int> &b){
+            return a[0] < b[0];
+        });
+        
+        //sort by start of each interval
+        //now check if end of current interval is <= start of next interval
+        // [[1, 2], [1, 6]] ==> [here 1 in second is < end of first] !!
+        // if current_interval_end < next_interval_start := there is overlap
+        //      set current_interval_end as max between current_end and next_end
+        // else := no overlap
+        //      set current_interval as ith interval
+        //      add current_interval to result
+        
+        auto current_interval = intervals[0];
+        
+        for(auto i=0; i<intervals.size(); i++) {
+            auto current_begin = current_interval[0];
+            auto current_end = current_interval[1];
+            auto next_begin = intervals[i][0];
+            auto next_end = intervals[i][1];
+            
+            if(next_begin <= current_end){
+                current_interval[1] = max(current_end, next_end);
+                cout<<current_interval[0]<<" "<<current_interval[1];     
+            }
+            else { // just merge as it is..
+                result.push_back(current_interval);
+                current_interval = intervals[i];
+            }
+        }
+        result.push_back(current_interval);
+        return result;
+    }
+};