对于宫格地图寻最短路径的一个广度搜索算法

import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map.Entry;
import java.util.Queue;

public class TestPath {

    public static void main(String[] args) {
        int arr[][] = { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
                                { 0, 0, 0, 1, 0, 0, 0, 0, 0, 0 },
                                { 0, 0, 0, 1, 0, 0, 0, 0, 0, 0 }, 
                                { 0, 0, 0, 1, 1, 0, 0, 0, 0, 0 }, 
                                { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
                                { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }, 
                                { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }, 
                                { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
                                { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }, 
                                { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } };        
        Queue<String> list = new ArrayDeque<>(100);
        arr[0][0] = 1;
        list.add("0,0,0");
        HashMap<Integer, ArrayList<String>> map = new HashMap<>();
        int dis = 1;
        Iterator<String> ite = list.iterator();

        while (ite.hasNext()) {
            String[] tm = ite.next().split(",");
            int i = Integer.parseInt(tm[0]);
            int j = Integer.parseInt(tm[1]);
            if (i + 1 > 0 && i + 1 < 10 && arr[i + 1][j] != 1) {
                dis = Integer.parseInt(tm[2]) + 1;
                String p = (i + 1) + "," + j + "," + dis;
                arr[i + 1][j] = 1;
                list.add(p);
                if (map.get(dis) == null) {
                    map.put(dis, new ArrayList<String>());
                }
                map.get(dis).add(p);
            }
            if (i - 1 > 0 && i - 1 < 10 && arr[i - 1][j] != 1) {
                dis = Integer.parseInt(tm[2]) + 1;
                String p = (i + 1) + "," + j + "," + dis;
                arr[i + 1][j] = 1;
                list.add(p);
                if (map.get(dis) == null) {
                    map.put(dis, new ArrayList<String>());
                }
                map.get(dis).add(p);
            }
            if (j + 1 > 0 && j + 1 < 10 && arr[i][j + 1] != 1) {
                dis = Integer.parseInt(tm[2]) + 1;
                String p = i + "," + (j + 1) + "," + dis;
                arr[i][j + 1] = 1;
                list.add(p);
                if (map.get(dis) == null) {
                    map.put(dis, new ArrayList<String>());
                }
                map.get(dis).add(p);
            }
            if (j - 1 > 0 && j - 1 < 10 && arr[i][j - 1] != 1) {
                dis = Integer.parseInt(tm[2]) + 1;
                String p = i + "," + (j + 1) + "," + dis;
                arr[i][j + 1] = 1;
                list.add(p);
                if (map.get(dis) == null) {
                    map.put(dis, new ArrayList<String>());
                }
                map.get(dis).add(p);
            }
            ite.remove();
            ite = list.iterator();
        }
        for (int i = 0; i < map.get(3).size(); i++) {
            System.out.println(map.get(3).get(i));
        }
        for (Entry<Integer, ArrayList<String>> m: map.entrySet()) {
            for (String str : m.getValue()) {
                if (str.startsWith("2,4")) {
                    System.out.println(str);
                }
            }
        }
    }

}

记录了各个点到(0,0)点的距离，其中数组中值为1的点是不可通过的点。