迷宫问题
Time Limit: 1000MS | Memory Limit: 65536K | |
Total Submissions: 6322 | Accepted: 3673 |
Description
定义一个二维数组:
int maze[5][5] = { 0, 1, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 1, 0, };
它表示一个迷宫,其中的1表示墙壁,0表示可以走的路,只能横着走或竖着走,不能斜着走,要求编程序找出从左上角到右下角的最短路线。
Input
一个5 × 5的二维数组,表示一个迷宫。数据保证有唯一解。
Output
左上角到右下角的最短路径,格式如样例所示。
Sample Input
0 1 0 0 0 0 1 0 1 0 0 0 0 0 0 0 1 1 1 0 0 0 0 1 0
Sample Output
(0, 0) (1, 0) (2, 0) (2, 1) (2, 2) (2, 3) (2, 4) (3, 4) (4, 4)
思路: DFS算法
import java.io.*;
import java.util.*;
public class Main {
public static int map[][] = new int[5][5];
public static int fx[] = { 0, 0, 1, -1 };
public static int fy[] = { 1, -1, 0, 0 };
public static int px, py;
public static void main(String[] args) {
Scanner sc = new Scanner(new BufferedInputStream(System.in));
while (sc.hasNextInt()) {
for (int i = 0; i < map.length; i++) {
for (int j = 0; j < map[i].length; j++) {
map[i][j] = sc.nextInt();
}
}
map[0][0] = 3;//标记走过
px = 0;
py = 0;
DFS(0, 0);
}
}
public static void DFS(int p1, int p2) {
if (p1 == map.length - 1 && p2 == map[0].length - 1){
out();
return;
}
else {
//四个方向进行判定
for (int i = 0; i < 4; i++) {
int px = p1 + fx[i];
int py = p2 + fy[i];
if (check(px, py)) {
map[px][py] = 3;//标记走过的路
DFS(px, py);
}
}
}
}
public static void out() {
for (int i = 0; i <5; i++) {
for (int j = 0; j <5; j++) {
if (map[i][j] == 3) {
System.out.println("(" + i + ", " + j + ")");
}
}
}
}
public static boolean check(int p1, int p2) {
if (p1 < 0 || p1 > map[0].length - 1 || p2 < 0 || p2 > map.length - 1
|| map[p1][p2] != 0)
return false;
else
return true;
}
}