华为 第二题 跳马 80%
// 感觉是没有考虑到边界情况,不是超时,是答案错误。不过感觉可以dp优化下,dfs纯暴搜确实捞
import java.util.Scanner;
public class Main {
static int m, n;
static long[][][] PATH;
static char[][] board;
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
m = sc.nextInt();
n = sc.nextInt();
sc.nextLine();
board = new char[m][n];
for (int i = 0; i < m; i++) {
String s = sc.nextLine();
board[i] = s.toCharArray();
}
PATH = new long[m][n][2];
for (int i = 0; i < m; i++) {
for (int j = 0; j < n; j++) {
PATH[i][j][0] = Integer.MAX_VALUE;
PATH[i][j][1] = Integer.MAX_VALUE;
}
}
dfs(0, 0, 0, 0);
System.out.println(Math.min(PATH[m-1][n-1][0],PATH[m-1][n-1][1]) >= Integer.MAX_VALUE ? -1 : Math.min(PATH[m-1][n-1][0],PATH[m-1][n-1][1]));
}
public static void dfs(int state, int i, int j, int path){
if (i >= 0 && j >= 0 && i < m && j < n && path < PATH[i][j][state] && board[i][j] != 'X') {
PATH[i][j][state] = path;
if (state == 0) {
dfs(state, i + 1, j, path + 1);
dfs(state, i , j+ 1, path + 1);
}
if (state == 1) {
dfs(state, i-2, j+1, path+1);
dfs(state, i+1, j+2, path+1);
dfs(state, i+1, j-2, path+1);
dfs(state, i+2, j+1, path+1);
dfs(state, i+2, j-1, path+1);
}
if (board[i][j] == 'S'){
state = toggle(state);
path++;
if (state == 0) {
dfs(state, i + 1, j, path + 1);
dfs(state, i , j+ 1, path + 1);
}
if (state == 1) {
dfs(state, i-2, j+1, path+1);
dfs(state, i+1, j+2, path+1);
dfs(state, i+2, j+1, path+1);
}
}
}
}
static int toggle(int x) {
return x == 0 ? 1 : 0;
}
}
#华为#