Create parallel-courses-iii.cpp

Author: kamyu104

C++/parallel-courses-iii.cpp

@@ -0,0 +1,37 @@
+// Time:  O(|V| + |E|)
+// Space: O(|E|)
+
+class Solution {
+public:
+    int minimumTime(int n, vector<vector<int>>& relations, vector<int>& time) {
+        vector<vector<int>> adj(n);
+        vector<int> in_degree(n);
+        for (const auto& relation : relations) {
+            adj[relation[0] - 1].emplace_back(relation[1] - 1);
+            ++in_degree[relation[1] - 1];
+        }
+        vector<int> q;
+        vector<int> dist(n);
+        for (int u = 0; u < n; ++u) {
+            if (in_degree[u]) {
+                continue;
+            }
+            q.emplace_back(u);
+            dist[u] = time[u];
+        }
+        while (!empty(q)) {
+            vector<int> new_q;
+            for (const auto& u : q) {
+                for (const auto& v : adj[u]) {
+                    dist[v] = max(dist[v], dist[u] + time[v]);
+                    --in_degree[v];
+                    if (!in_degree[v]) {
+                        new_q.emplace_back(v);
+                    }
+                }
+            }
+            q = move(new_q);
+        }
+        return *max_element(cbegin(dist), cend(dist));
+    }
+};