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DetectCycleInDirectedGraph.cpp
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DetectCycleInDirectedGraph.cpp
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// Detect cycle in a directed graph
// Given a Directed Graph with V vertices (Numbered from 0 to V-1) and E edges,
// check whether it contains any cycle or not.
// { Driver Code Starts
#include<bits/stdc++.h>
using namespace std;
// } Driver Code Ends
class Solution
{
public:
//Function to detect cycle in a directed graph.
bool cyclic(int i, int V, vector<int> adj[],bool visited[], bool inTheCall[])
{
visited[i]=true;
inTheCall[i]=true;
for(int j =0;j<adj[i].size();j++)
{
if(!visited[adj[i][j]] && cyclic(adj[i][j],V,adj,visited,inTheCall))
{
return true;
}
else{
if(inTheCall[adj[i][j]])
return true;
}
}
inTheCall[i]=false;
return false;
}
bool isCyclic(int V, vector<int> adj[])
{
bool visited[V];
bool inTheCall[V];
for(int i=0;i<V;i++)
{
visited[i]=false;
inTheCall[i]= false;
}
for(int i =0;i<V;i++)
{ if(!visited[i]){
if(cyclic(i,V,adj,visited,inTheCall))
return true;
}
}
return false;
}
};
// { Driver Code Starts.
int main()
{
int t;
cin >> t;
while(t--)
{
int V, E;
cin >> V >> E;
vector<int> adj[V];
for(int i = 0; i < E; i++)
{
int u, v;
cin >> u >> v;
adj[u].push_back(v);
}
Solution obj;
cout << obj.isCyclic(V, adj) << "\n";
}
return 0;
}
// } Driver Code Ends