Added Solution To Topological Sort using C++

Topological_Sort.cpp

@@ -0,0 +1,87 @@
+// The topological sort algorithm takes a directed graph and returns an array of the nodes where each node appears before all the nodes it points to
+
+#include<bits/stdc++.h>
+using namespace std;
+
+vector<int> topoSort(int V, vector<int> adj[])
+{
+    vector<int> indegree(V,0);
+
+    for(int i = 0; i<V; i++)
+    {
+        for(auto x: adj[i])
+        {
+            indegree[x]++;
+        }
+    }
+
+    queue<int> q;
+    for(int i = 0; i<V; i++)
+    {
+        if(indegree[i] == 0)
+        {
+            q.push(i);
+        }
+    }
+
+    vector<int> topo;
+
+    while(!q.empty())
+    {
+        int node = q.front();
+        q.pop();
+        topo.push_back(node);
+
+        for(auto x: adj[node])
+        {
+            indegree[x]--;
+            if(indegree[x] == 0)
+            {
+                q.push(x);
+            }
+        }
+    }
+    return topo;
+}    
+
+int check(int V, vector <int> &res, vector<int> adj[]) {
+
+    if(V!=res.size())
+    return 0;
+
+    vector<int> map(V, -1);
+    for (int i = 0; i < V; i++) {
+        map[res[i]] = i;
+    }
+    for (int i = 0; i < V; i++) {
+        for (int v : adj[i]) {
+            if (map[i] > map[v]) return 0;
+        }
+    }
+    return 1;
+}
+
+int main() {
+    int T;
+    cin >> T;
+    while (T--) {
+        int N, E;
+        cin >> E >> N;
+        int u, v;
+
+        vector<int> adj[N];
+
+        for (int i = 0; i < E; i++) {
+            cin >> u >> v;
+            adj[u].push_back(v);
+        }
+        vector <int> res = topoSort(N, adj);
+
+        cout << check(N, res, adj) << endl;
+    }
+
+    return 0;
+}
+
+// Time Complexity: O(V+E)
+// Space Complexity: O(V)

tempCodeRunnerFile.cpp

@@ -0,0 +1,82 @@
+#include<bits/stdc++.h>
+using namespace std;
+
+vector<int> topoSort(int V, vector<int> adj[])
+{
+    vector<int> indegree(V,0);
+
+    for(int i = 0; i<V; i++)
+    {
+        for(auto x: adj[i])
+        {
+            indegree[x]++;
+        }
+    }
+
+    queue<int> q;
+    for(int i = 0; i<V; i++)
+    {
+        if(indegree[i] == 0)
+        {
+            q.push(i);
+        }
+    }
+
+    vector<int> topo;
+
+    while(!q.empty())
+    {
+        int node = q.front();
+        q.pop();
+        topo.push_back(node);
+
+        for(auto x: adj[node])
+        {
+            indegree[x]--;
+            if(indegree[x] == 0)
+            {
+                q.push(x);
+            }
+        }
+    }
+    return topo;
+}    
+
+int check(int V, vector <int> &res, vector<int> adj[]) {
+
+    if(V!=res.size())
+    return 0;
+
+    vector<int> map(V, -1);
+    for (int i = 0; i < V; i++) {
+        map[res[i]] = i;
+    }
+    for (int i = 0; i < V; i++) {
+        for (int v : adj[i]) {
+            if (map[i] > map[v]) return 0;
+        }
+    }
+    return 1;
+}
+
+int main() {
+    int T;
+    cin >> T;
+    while (T--) {
+        int N, E;
+        cin >> E >> N;
+        int u, v;
+
+        vector<int> adj[N];
+
+        for (int i = 0; i < E; i++) {
+            cin >> u >> v;
+            adj[u].push_back(v);
+        }
+        vector <int> res = topoSort(N, adj);
+
+        cout << check(N, res, adj) << endl;
+    }
+
+    return 0;
+}