LC - 207. Course Schedule

class Solution {
public:
    
    bool detectCycle_dfs( vector<vector<int>>& adjList, int node, vector<bool>& vis, vector<bool>& inPath)
    {
        vis[node] = true;
        inPath[node] = true;
        for(auto child : adjList[node])
        {
            if(!vis[child])
            {
                bool containsCycle = detectCycle_dfs(adjList, child, vis, inPath);
                if(containsCycle) return true;
            }
            else if(inPath[child])
            {
                return true;
            }
        }
        inPath[node] = false;
        return  false;
    }
    
    bool canFinish(int numCourses, vector<vector<int>>& prerequisites) 
    {
        vector<vector<int>> adjList(numCourses);
        vector<bool> vis(numCourses, false);
        vector<bool> inPath(numCourses,false);
        for(int i = 0; i < prerequisites.size(); i++)
        {
            adjList[prerequisites[i][1]].push_back(prerequisites[i][0]);
        }
        for(int i = 0; i < numCourses; i++)
        {
            if(!vis[i])
            {
                if(detectCycle_dfs(adjList,i,vis,inPath)) return false;
            }
        }
        return true;
    }
};