Method runDijkstra

modifiedGraphEdges.java:53–87

(int n, int source, int destination)

    // Dijkstra's algorithm to find the shortest path from source to destination
    private int runDijkstra(int n, int source, int destination) {
        int[] minDistance = new int[n];
        boolean[] visited = new boolean[n];
        // sort in increasing order of edge weight
        // [u,w] (node, weight to node)
        PriorityQueue<int[]> queue = new PriorityQueue<>(new Comparator<int[]>(){
            public int compare(int a[], int b[]){
                return a[1] - b[1];
            }
        });

        Arrays.fill(minDistance, INF);
        minDistance[source] = 0;
        queue.add(new int[] { source, 0 });

        while (!queue.isEmpty()) {
            int[] curr = queue.poll();
            int u = curr[0];
            int d = curr[1];

            if (d > minDistance[u]) continue;

            for (int[] neighbour : graph[u]) {
                int v = neighbour[0];
                int weight = neighbour[1];

                if (d + weight < minDistance[v]) {
                    minDistance[v] = d + weight;
                    queue.add(new int[] { v, minDistance[v] });
                }
            }
        }

        return minDistance[destination];
    }
}