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public class Dijkstra {
  private int[][] matrix ;
  private boolean[] visted;
  private int[] preVertex;
  private int[] distance;
  private int vertexLen = 4;
  public static final int MAX = 10000;
  public Dijkstra() {
    matrix = new int[vertexLen][vertexLen];
    matrix[0] = new int[]{MAX, 1, 10, MAX};
    matrix[1] = new int[]{1, MAX, 2, 8};
    matrix[2] = new int[]{10, 2, MAX, 3};
    matrix[3] = new int[]{MAX, 8, 3, MAX};

    visted = new boolean[vertexLen];
    preVertex = new int[vertexLen];
    distance = new int[vertexLen];
    Arrays.fill(distance, MAX);
  }
  public void setStart(int startIndex) {
    distance[startIndex] = 0;
    visted[startIndex] = true;
  }
  public void dijkstra(int index) {
    int len = 0;
    for (int i = 0; i < matrix[index].length; i++) {
      len = distance[index] + matrix[index][i];
      if (!visted[i] && len < distance[i]) {
        distance[i] = len;
        preVertex[i] = index;
      }
    }
  }

  public static void main(String[] args) {
    Dijkstra dijkstra = new Dijkstra();
    dijkstra.setStart(0);
    dijkstra.dijkstra(0);
    System.out.println(Arrays.toString(dijkstra.distance));
    for (int i = 0; i < dijkstra.vertexLen - 1; i++) {
      int vertex = dijkstra.findMinPathVertex();
      System.out.println("vertex = " + vertex);
      dijkstra.dijkstra(vertex);
      System.out.println(Arrays.toString(dijkstra.distance));
      System.out.println(Arrays.toString(dijkstra.preVertex));
      System.out.println("============");
    }
  }

  public int findMinPathVertex() {
    int min = MAX;
    int vertex = 0;
    for (int i = 0; i < vertexLen; i++) {
      if (!visted[i] && distance[i] < min) {
        min = distance[i];
        vertex = i;
      }
    }
    visted[vertex] = true;
    return vertex;
  }
}