Cycle Detection in Directed Graph.cpp

C++/Cycle Detection in Directed Graph.cpp

@@ -0,0 +1,71 @@
+#include <bits/stdc++.h>
+using namespace std;
+#define ll long long
+#define mod 1000000007
+#define mod9 998244353
+#define raftaar                       \
+    ios_base::sync_with_stdio(false); \
+    cin.tie(NULL);                    \
+    cout.tie(NULL)
+#define endl "\n"
+bool dfs(int node, vector<int> adj[], vector<bool> &vis, vector<int> &check)
+{
+    vis[node] = 1;
+    check[node] = 1;
+    for (auto x : adj[node])
+    {
+        if (!vis[x])
+        {
+            if (dfs(x, adj, vis, check))
+            {
+                return true;
+            }
+        }
+        if (check[x])
+        {
+            return true;
+        }
+    }
+    check[node] = 0;
+    return false;
+}
+bool isCyclic(int V, vector<int> adj[])
+{
+    vector<bool> vis(V, 0);
+    vector<int> check(V, 0);
+
+    for (int i = 0; i < V; i++)
+    {
+        if (!vis[i])
+        {
+            if (dfs(i, adj, vis, check))
+            {
+                return true;
+            }
+        }
+    }
+
+    return false;
+}
+int main()
+{
+    raftaar;
+    int node, edges;
+    cin >> node >> edges;
+    vector<int> adj[node];
+    for (int i = 0; i < edges; i++)
+    {
+        int u, v;
+        cin >> u >> v;
+        adj[u].push_back(v);
+    }
+    bool ans = isCyclic(node, adj);
+    if (ans)
+    {
+        cout << "The Graph contain cycle" << endl;
+    }
+    else
+    {
+        cout << "The Graph does not contain cycle" << endl;
+    }
+}