Merge pull request AllAlgorithms#205 from raunak96/master

Added Topological Sort

Author: abranhe

graphs/toposort.cpp

@@ -0,0 +1,45 @@
+#include <bits/stdc++.h>
+using namespace std;
+vector<int> adj[10001];
+priority_queue<int,vector<int>,greater<int> >q;
+queue<int>a;
+bool visited[10001];
+int indegree[10001];
+int main()
+{
+int n,m,u,v;
+scanf("%d%d",&n,&m);
+while(m--)
+{
+ scanf("%d%d",&u,&v);
+ adj[u].push_back(v);
+ indegree[v]++;
+}
+for(int i=1;i<=n;i++)
+ if(!indegree[i])
+ q.push(i);
+int k=0;
+while(!q.empty())
+{
+ int u=q.top();
+ q.pop();
+ a.push(u);
+ for(auto it:adj[u])
+ {
+ indegree[it]--;
+ if(!indegree[it])
+ q.push(it);
+ }
+ ++k;
+}
+if(k!=n)
+ printf("Sandro fails.");
+else
+{
+ while(!a.empty())
+ {
+ printf("%d ",a.front());
+ a.pop();
+ }
+}
+}