杭电 1026 Ignatius and the Princess I BFS 搜索 JAVA

题意：n*m迷宫，求从(0,0)到(n-1,m-1)的最少时间。'X'是墙，'.'是空地，'1'-'9'表示有怪物，消灭之需要数字对应的时间。

package DFS;import java.util.PriorityQueue;import java.util.Scanner;import java.util.Stack;public class HD1026 {    int n,    m,    mins;    char[][] maze;    int[][] vis;    int[] dr = { - 1,        0,        1,        0    };    int[] dc = {        0,        -1,        0,        1    };    Point[][] roads;    int success;    public static void main(String[] args) {        new HD1026().run();    }    public void run() {        Scanner scanner = new Scanner(System. in );        while (scanner.hasNextInt()) {            n = scanner.nextInt();            m = scanner.nextInt();            maze = new char[n][m];            vis = new int[n][m];            roads = new Point[n][m];            String line;            scanner.nextLine();            for (int i = 0; i < n; i++) {                line = scanner.nextLine();                for (int j = 0; j < m; j++) {                    maze[i][j] = line.charAt(j);                    vis[i][j] = 0;                }            }            success = 0;            bfs();            if (success == 1) {                System.out.printf("It takes %d seconds to reach the target position, let me show you the way.\n", mins);                print();            } else {                System.out.printf("God please help our poor hero.\nFINISH\n");            }        }        scanner.close();    }    public void bfs() {        Point point = new Point();        PriorityQueue < Point > queue = new PriorityQueue <Point >();        queue.offer(point);        vis[0][0] = 1;        while (!queue.isEmpty()) {            point = queue.poll();            if (point.x == n - 1 && point.y == m - 1) {                mins = point.cnt;                success = 1;                return;            }            for (int d = 0; d < 4; d++) {                int rtemp = point.x + dr[d];                int ctemp = point.y + dc[d];                if (rtemp >= 0 && rtemp < n && ctemp >= 0 && ctemp < m && vis[rtemp][ctemp] != 1 && maze[rtemp][ctemp] != 'X') {                    vis[rtemp][ctemp] = 1;                    roads[rtemp][ctemp] = new Point(point.x, point.y, point.cnt);                    if (maze[rtemp][ctemp] == '.') {                        queue.offer(new Point(rtemp, ctemp, point.cnt + 1));                    } else {                        queue.offer(new Point(rtemp, ctemp, point.cnt + (maze[rtemp][ctemp] - '0' + 1)));                    }                }            }        }    }    public void print() {        Stack < Point > stack = new Stack <Point >();        Point temp = roads[n - 1][m - 1];        stack.push(new Point(n - 1, m - 1, mins));        while (temp.x != 0 || temp.y != 0) {            stack.push(temp);            temp = roads[temp.x][temp.y];        }        int t = 1;        while (!stack.empty()) {            temp = stack.peek();            stack.pop();            if (maze[temp.x][temp.y] == '.') System.out.printf("%ds:(%d,%d)->(%d,%d)\n", t++, roads[temp.x][temp.y].x, roads[temp.x][temp.y].y, temp.x, temp.y);            else {                System.out.printf("%ds:(%d,%d)->(%d,%d)\n", t++, roads[temp.x][temp.y].x, roads[temp.x][temp.y].y, temp.x, temp.y);                int k = maze[temp.x][temp.y] - '0';                while (k--!=0) System.out.printf("%ds:FIGHT AT (%d,%d)\n", t++, temp.x, temp.y);            }        }        System.out.printf("FINISH\n");    }    class Point implements Comparable < Point > {        int x,        y,        cnt;        public Point() {            x = 0;            y = 0;            cnt = 0;        }        public Point(int x, int y, int cnt) {            this.x = x;            this.y = y;            this.cnt = cnt;        } public int compareTo(Point o) {                   return this.cnt > o.cnt ? 1 : -1;        }    }}