Solution to #29

Solutions/S29.cpp

@@ -0,0 +1,27 @@
+bool canFinish(int numCourses, vector<vector<int>>& prerequisites) {
+    list<int> adj[numCourses];
+    vector<int> indeg(numCourses, 0), res;
+    queue<int> q;
+    int n = prerequisites.size();
+    for(int i = 0; i < n; i++)
+    {
+        int a = prerequisites[i][0], b = prerequisites[i][1];
+        adj[b].push_back(a);
+        indeg[a]++;
+    }
+    for(int i = 0; i < numCourses; i++)
+    {
+        if(indeg[i] == 0) {q.push(i);}
+    }
+    while(!q.empty())
+    {
+        int k = q.front();
+        res.push_back(k);
+        q.pop();
+        for(auto it = adj[k].begin(); it != adj[k].end(); it++)
+        {
+            if(--indeg[*it] == 0) q.push(*it);
+        }
+    }
+    return (res.size() == numCourses);
+}