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dijkstra added #204

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57 changes: 57 additions & 0 deletions graphs/dijkstra.dart
Original file line number Diff line number Diff line change
@@ -0,0 +1,57 @@
const int MAX_VALUE = 1000000;
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Add a reference link to checkout the algorithm (ex: Wikipedia link to dijkstra)


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());
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avoid print statements

}
}
}

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();
Comment on lines +43 to +55
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Could you please add few test cases?

dij.dijkstra(graph, 0);
}