求最短通路值

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import java.util.LinkedList;import java.util.Queue;/** * Created by lxw, liwei4939@126.com on 2017/11/3. * 求最短通路值 * 广度优先搜索 */public class minPath {    public int minPathValue(int[][] m){        if(m == null || m.length == 0|| m[0].length ==0 ||                m[0][0] != 1 || m[m.length-1][m[0].length - 1] != 1){            return 0;        }        int res = 0;        int[][] map = new int[m.length][m[0].length];        map[0][0] = 1;        Queue<Integer> rQ = new LinkedList<Integer>();        Queue<Integer> cQ = new LinkedList<Integer>();        rQ.add(0);        cQ.add(0);        int r = 0;        int c = 0;        while (!rQ.isEmpty()){            r = rQ.poll();            c = cQ.poll();            if(r == m.length- 1 && c == m[0].length - 1){                return map[r][c];            }            walkTo(map[r][c], r - 1, c, m, map, rQ, cQ);            walkTo(map[r][c], r + 1, c, m, map, rQ, cQ);            walkTo(map[r][c], r, c - 1, m, map, rQ, cQ);            walkTo(map[r][c], r, c + 1, m, map, rQ, cQ);        }        return res;    }    public void walkTo(int pre, int toR, int toC, int[][] m,                       int[][] map, Queue<Integer> rQ, Queue<Integer> cQ){        if(toR < 0 || toR == m.length || toC < 0 || toC == m[0].length ||                m[toR][toC] != 1 || map[toR][toC] != 0){            return;        }        map[toR][toC] = pre + 1;        rQ.add(toR);        cQ.add(toC);    }    public static void main(String[] args){        minPath tmp = new minPath();        int[][] matrix = {{1, 0, 1, 1, 1},{1, 0, 1, 0, 1},                {1, 1, 1, 0, 1},{0, 0, 0, 0, 1}};        System.out.println(tmp.minPathValue(matrix));    }}
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