广度优先搜索

import java.util.LinkedList;
//邻接矩阵表示图  广度优先搜索
public class BFS {
 public static void main(String  [] args)
 {
  int n = 5;
  int [][] matrix = 
    {
     {0, 1, 1, 0,0},
     {1, 0, 0, 0,1},
     {1, 0, 0, 1,0},
     {0, 0, 1, 0,0}, 
     {0, 1, 0, 0,0},
    };
  
  boolean [] visited = new boolean [n];
  for (int i = 0; i < n ; i ++)
   visited [i] = false;
  
  BFS bfs = new BFS();
  for (int i = 0; i < n; i ++)
  {
   if (!visited [i])//如果没有被访问
   {
    bfs.BfsTrack(matrix, visited, n, i);
   }
  }
 }
 
 private void BfsTrack(int [][] matrix, boolean [] visited, int n, int i)
 {
  LinkedList<Integer> queue = new LinkedList<Integer>();
  queue.add(i);
  visited[i] = true;
  System.out.print(" " + (i+1) + " ");
  while(queue.size()!=0)//队列中还有数据
  {
   int k = queue.pollFirst();//取出队首数据
   for (int j = 0; j < n; j ++)
   {
    if (matrix[k][j] != 0 && !visited[j])//访问与当前节点相邻的节点
    {
     queue.add(j);//把相邻节点入队
     visited[j] = true;//标记为已访问节点
     System.out.print(" " + (j+1) + " ");
    }
   }
  }  
  //System.out.println(""); 
 }  
}