[C++] Graph Algorithms: Flyod-Warshall Algorithm (Shortest Path)

C++/README.md

@@ -6,6 +6,7 @@
 * Segment Tree
 
 # Graph Algorithms
+* Flyod-Warshall Algorithm _(Shortest Path)_
 * Topological Sort _(Depth-First Search)_
 * Topological Sort _(Kahn's Algorithm)_
 * Transitive Closure

C++/graph_algorithms/CMakeLists.txt

@@ -1,5 +1,7 @@
 target_sources(programming
     PRIVATE
+    shortest_path.h
+    shortest_path.cpp
     topological_sort.h
     topological_sort.cpp
     transitive_closure.h

C++/graph_algorithms/shortest_path.cpp

@@ -0,0 +1,47 @@
+// Copyright 2024 Aman Mehara
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "shortest_path.h"
+
+#include <algorithm>
+#include <climits>
+#include <vector>
+
+namespace mehara::graph {
+
+using namespace std;
+
+vector<vector<int>> flyod_warshall_algorithm(int n,
+                                             const std::vector<edge>& edges)
+{
+    vector<vector<int>> dist(n, vector<int>(n, INT_MAX));
+    for (const auto& e : edges) {
+        dist[e.to][e.from] = e.weight;
+    }
+    for (int i = 0; i < n; i++) {
+        dist[i][i] = true;
+    }
+    for (int k = 0; k < n; k++) {
+        for (int i = 0; i < n; i++) {
+            for (int j = 0; j < n; j++) {
+                if (dist[i][k] < INT_MAX && dist[k][j]) {
+                    dist[i][j] = min(dist[i][j], dist[i][k] + dist[k][j]);
+                }
+            }
+        }
+    }
+    return dist;
+}
+
+} // namespace mehara::graph

C++/graph_algorithms/shortest_path.h

@@ -0,0 +1,33 @@
+// Copyright 2024 Aman Mehara
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef MEHARA_SHORTEST_PATH_H_
+#define MEHARA_SHORTEST_PATH_H_
+
+#include <vector>
+
+namespace mehara::graph {
+
+struct edge {
+    int from;
+    int to;
+    int weight;
+};
+
+std::vector<std::vector<int>>
+flyod_warshall_algorithm(int n, const std::vector<edge>& edges);
+
+} // namespace mehara::graph
+
+#endif // MEHARA_SHORTEST_PATH_H_