Алгоритм Дейкстры

cmd/bin/src/graph.dart

@@ -89,6 +89,7 @@ class Dot {
 }
 
 class Graphs {
+  static const int intMax = 0x7fffffffffffffff;
   //Data
   String _name = "Undefined"; //Имя
   int _amount = 0; //Количество вершин
@@ -151,6 +152,9 @@ class Graphs {
     if (from <= 0 || from > _amount || to <= 0 && to > _amount) {
       return "Can't find specified path";
     }
+    if (!_dots[from - 1].hasConnection(to)) {
+      return "Already no connection between $from and $to";
+    }
     _dots[from - 1].delPath(to);
     if (!_oriented) {
       _dots[to - 1].delPath(from);
@@ -652,28 +656,41 @@ class Graphs {
     return label;
   }
 
-  void dijkstra(int source) {
+  List<int?> dijkstra(int from) {
     /*
-      create vertex set Q;
+	int n;
+	... чтение n ...
+	//vector<vector<pair<int,int>>> g(_amount);
+  */
+    List<int?> d = List<int?>.filled(_amount, intMax);
+    List<int> p = List<int>.filled(_amount, -1);
 
-      for each vertex v in Graph{            
-          dist[v] ← INFINITY ;                
-          prev[v] ← UNDEFINED  ;            
-          add v to Q;}                     
-      dist[source] ← 0;                       
-     
-      while Q is not empty{
-         u ← vertex in Q with min dist[u]   
-                                             
-          remove u from Q
-         
-          for each neighbor v of u still in Q{
-              alt ← dist[u] + length(u, v);
-              if alt < dist[v]:  {            
-                  dist[v] ← alt;
-                  prev[v] ← u;}
-  }}
-      return dist[], prev[]*/
+    d[from - 1] = 0;
+    List<bool> u = List<bool>.filled(_amount, false);
+    for (int i = 0; i < _amount; ++i) {
+      int v = -1;
+      for (int j = 0; j < _amount; ++j) {
+        // int t;
+        if (!u[j] && (v == -1 || d[j]! < d[v]!)) {
+          v = j;
+        }
+      }
+      if (d[v] == intMax) break;
+      u[v] = true;
+      for (int to in _dots[v].getL().keys) {
+        int len = _dots[v].getL()[to]!;
+        if (!_useLength && len == 0) len = 1;
+        if (d[v]! + len < d[to - 1]!) {
+          d[to - 1] = d[v]! + len;
+          p[to - 1] = v;
+        }
+      }
+    }
+    for (int i = 0; i < d.length; i++) {
+      // подумать как убрать эту часть
+      if (d[i] == intMax) d[i] = null;
+    }
+    return d;
   }
   //************Алгоритмы************
 }