Merge pull request begeekmyfriend#19 from mdrazak2001/207-course-Schedule-CPP

Adding C++ Implementation for 207.Course Schedule

Author: begeekmyfriend

0207_course_schedule/course_schedule.cc

@@ -0,0 +1,37 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+class Solution {
+public:
+    bool isCycle(int course, vector<vector<int>>& adj, vector<int>& visited) {
+        if(visited[course] == 2) return true ;
+        if(visited[course] == 1) return false ;
+        visited[course] = 2 ;
+        for(auto connectedCourse : adj[course]) {
+            if(isCycle(connectedCourse, adj, visited)) {
+                return true ;
+            }
+        }
+        visited[course] = 1 ;
+        return false ;
+    }    
+    
+    bool canFinish(int numCourses, vector<vector<int>>& prerequisites) {
+        vector<vector<int>> adj(numCourses) ;
+        for(auto courses : prerequisites) {
+            auto course1 = courses[0] ;
+            auto course2 = courses[1] ;
+            adj[course2].push_back(course1) ;
+        }
+        vector<int> visited(numCourses, 0) ;
+        for(int course = 0 ; course < numCourses ; course++) {
+            if(!visited[course]) {
+                if(isCycle(course, adj, visited)) {
+                    return false;
+                }
+            }
+        }
+        return true ;
+    }
+};