TopologicalSorting.cpp

classicalAlgos/TopologicalSorting.cpp

@@ -0,0 +1,66 @@
+#include<bits/stdc++.h>
+using namespace std;
+#define ll long long 
+#define pb push_back
+#define ppb pop_back
+#define sp <<" "<<
+#define yes cout<<"YES"<<endl
+#define no cout<<"NO"<<endl
+#define min3(a, b, c) min(c, min(a, b))
+#define min4(a, b, c, d) min(d, min(c, min(a, b)))
+#define all(c) c.begin(), c.end()
+#define INF 1e18
+#define mod 1000000007
+#define pi (3.141592653589)
+
+typedef pair<ll,pair<ll,ll>>ppl;
+typedef pair<ll,ll>pl; 
+typedef vector<ll> vll;
+
+const int M = 1e9+7;
+const int N = 1e5+5;
+vector<int>g[N];
+vector<int>vis;
+void toposort_dfs(int source, stack<int>&st){
+    vis[source] = true;
+    for(auto child:g[source]){
+        if(vis[child]) continue;
+        toposort_dfs(child,st);
+    }
+    st.push(source);
+}
+void solve(int p)
+{
+    //taking input for the graph
+    int n,m;        //m = number of nodes, m = number of edges
+    cin>>n>>m;
+    for(int i = 0;i<m;i++){
+        int a,b;
+        cin>>a>>b;
+        g[a].push_back(b);
+    }
+    vis.resize(n+1,false);
+    for(int i = 0;i<n;i++){
+        if(vis[i]) continue;
+        toposort_dfs(i,st);
+    }
+    vector<int>v;
+    while(!st.emtpy()){
+        v.push_back(st.top());
+        st.pop();
+    }
+    for(int i = 0;i<v.size();i++){
+        cout<<v[i]<<" ";
+    }
+    return;
+}
+int main()
+{
+    int t = 1;
+    cin>>t;
+    int p = 1;
+    while (t--)
+    {
+        solve(p++);
+    }
+}