Create skyline.cpp

Author: TheSYNcoder

Solutions/skyline.cpp

@@ -0,0 +1,34 @@
+class Solution {
+public:
+    // Solution hint : https://briangordon.github.io/2014/08/the-skyline-problem.html
+    vector<vector<int>> getSkyline(vector<vector<int>>& buildings) {
+        set<vector<int>> cp;        
+        for ( auto x : buildings ){
+            cp.insert({ x[0] , x[1],  x[2], 1});
+            cp.insert({ x[1] , x[0] , x[2] ,0});            
+        }
+        set< vector<int> > heap;
+        vector<vector<int>> ans;
+        for ( auto x : cp){
+                    
+            if ( x[3]) {
+                heap.insert({ x[2], x[0] , x[1]});
+            }
+            else{
+                heap.erase(heap.find({x[2] , x[1] , x[0]}));
+            } 
+            if ( !ans.empty() && ans.back()[0] == x[0]){
+                    ans.pop_back();
+            }
+            if ( heap.empty()){
+                ans.push_back({x[0] ,0 });    
+            }
+            else
+            {   
+                if ( ans.empty() || ans.back()[1] !=(*heap.rbegin())[0])
+                    ans.push_back({x[0] , (*heap.rbegin())[0]});
+            }
+        }
+        return ans;
+    }
+};