图的深度优先搜索和广度优先搜索模板

一、邻接矩阵实现：

package Template;
//邻接矩阵实现图的广搜和深搜
import java.util.*;

public class Map1 {

	/**
	 * @param args
	 */
	static int[][] G;
	static int k;
	static boolean[] visited;
	static boolean isfirst = true;
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);

		int n;
		int m, t;
		n = sc.nextInt();
		while (n-->0) {
			isfirst = true;
			k = sc.nextInt();
			m = sc.nextInt();
			t = sc.nextInt();
			G = new int[k][k];
			visited = new boolean[k];
			for (int i = 0; i < m; i++) {
				int u = sc.nextInt();
				int v = sc.nextInt();
				G[u][v] = 1;
				G[v][u] = 1;
			}
			bfs(t);
			System.out.println();
//			visited = new boolean[k];
//			dfs(t);
//			System.out.println();
		}
	}
//广搜
	public static void bfs(int v) {
		boolean isfirst = true;
		LinkedList que = new LinkedList();
		que.add(v);
		while (!que.isEmpty()) {
			v = que.poll();
			if (isfirst) {
				System.out.print(v);
				isfirst = false;
			} else
				System.out.print(" " + v);
			visited[v] = true;
			for (int i = 0; i < k; i++) {
				if (G[v][i] == 1 && !visited[i]) {
					que.add(i);
					visited[i] = true;
				}
			}
		}

	}
	//深搜
	public static void dfs(int v) {
		visited[v] = true;
		if (isfirst) {
			System.out.print(v);
			isfirst = false;
		} else
			System.out.print(" " + v);
		for (int i = 0; i < k; i++) {
			if (G[v][i] == 1 && !visited[i])
				dfs(i);
		}
	}

}

 

二邻接表实现：

package Template;

//邻接表实现图的广搜和深搜
import java.util.*;

public class Map2 {

	static class Edge implements Comparable {
		int to;// 边的终点

		public Edge(int t) {
			to = t;
		}

		@Override
		public int compareTo(Edge o) {
			return to - o.to;
		}

	}

	static class VNode {
		int from;// 边的起点
		PriorityQueue pri = new PriorityQueue();

		public VNode(int v) {
			from = v;
		}
	}

	static VNode[] V;
	static int k;// 图的顶点
	static boolean[] visited;
	static boolean isfirst;

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n;
		int m, t;
		n = sc.nextInt();
		while (n-- > 0) {
			k = sc.nextInt();
			m = sc.nextInt();
			t = sc.nextInt();
			visited = new boolean[k];
			isfirst = true;
			V = new VNode[k];
			for (int i = 0; i < k; i++)
				V[i] = new VNode(i);
			for (int i = 0; i < m; i++) {
				int u = sc.nextInt();// 起点
				int v = sc.nextInt();// 终点
				Edge e = new Edge(v);
				V[u].pri.add(e);
				// 无向图的对称
				e = new Edge(u);
				V[v].pri.add(e);
			}
			bfs(t);
			// dfs(t);
			System.out.println();
		}

	}

	// 广搜
	public static void bfs(int v0) {
		boolean isfirst = true;
		Queue que = new LinkedList();
		que.add(v0);
		while (!que.isEmpty()) {
			v0 = que.poll();
			if (!visited[v0]) {
				if (isfirst) {
					System.out.print(v0);
					isfirst = false;
				} else
					System.out.print(" " + v0);
				visited[v0] = true;
			}
			
			while (!V[v0].pri.isEmpty()) {
				Edge e = V[v0].pri.poll();// 得到以v为起点的终点链表
				if (!visited[e.to])
					que.add(e.to);
			}
		}
	}

	// 深搜
	public static void dfs(int v0) {

		visited[v0] = true;
		if (isfirst) {
			System.out.print(v0);
			isfirst = false;
		} else
			System.out.print(" " + v0);
		
		while (!V[v0].pri.isEmpty()) {
			Edge p = V[v0].pri.poll();
			if (!visited[p.to])
				dfs(p.to);
		}
	}

}