From d3885afb0ce0cf65ec0ed2f0f709c45a11c7f39b Mon Sep 17 00:00:00 2001
From: Hasan Zonuzi <hasanzon@yahoo.com>
Date: Tue, 18 Oct 2022 14:53:09 +0330
Subject: [PATCH] feat: add dijkstra to graph algorithms

---
 graphs/dijkstra.dart | 57 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)
 create mode 100644 graphs/dijkstra.dart

diff --git a/graphs/dijkstra.dart b/graphs/dijkstra.dart
new file mode 100644
index 00000000..eca89d26
--- /dev/null
+++ b/graphs/dijkstra.dart
@@ -0,0 +1,57 @@
+const int MAX_VALUE = 1000000;
+
+class Dijkstra {
+  int minDist(List<int> dist, List<bool> visited) {
+    int min = MAX_VALUE, min_index = -1;
+    for (int v = 0; v < dist.length; v++) {
+      if (visited[v] == false && dist[v] <= min) {
+        min = dist[v];
+        min_index = v;
+      }
+    }
+    return min_index;
+  }
+
+  void dijkstra(List<List<int>> graph, int src) {
+    List<int> dist = List.filled(graph.length, MAX_VALUE);
+    List<bool> visited = List.filled(graph.length, false);
+
+    dist[src] = 0;
+    for (int count = 0; count < graph.length - 1; count++) {
+      int u = minDist(dist, visited);
+      visited[u] = true;
+      for (int v = 0; v < graph.length; v++) {
+        if (!visited[v] &&
+            graph[u][v] != 0 &&
+            dist[u] != MAX_VALUE &&
+            dist[u] + graph[u][v] < dist[v]) {
+          dist[v] = dist[u] + graph[u][v];
+        }
+      }
+    }
+    printSolution(dist);
+  }
+
+  void printSolution(List<int> dist) {
+    print("Vertex   Distance from Source");
+    for (int i = 0; i < dist.length; i++) {
+      print(i.toString() + " ------------> " + dist[i].toString());
+    }
+  }
+}
+
+void main() {
+  List<List<int>> graph = [
+    [0, 4, 0, 0, 0, 0, 0, 8, 0],
+    [4, 0, 8, 0, 0, 0, 0, 11, 0],
+    [0, 8, 0, 7, 0, 4, 0, 0, 2],
+    [0, 0, 7, 0, 9, 14, 0, 0, 0],
+    [0, 0, 0, 9, 0, 10, 0, 0, 0],
+    [0, 0, 4, 14, 10, 0, 2, 0, 0],
+    [0, 0, 0, 0, 0, 2, 0, 1, 6],
+    [8, 11, 0, 0, 0, 0, 1, 0, 7],
+    [0, 0, 2, 0, 0, 0, 6, 7, 0]
+  ];
+  Dijkstra dij = new Dijkstra();
+  dij.dijkstra(graph, 0);
+}