UVA 816 Abbott's Revenge

https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=757

BFS,有点复杂，看着别人的代码调试了半天，争取自己写出来。

import java.util.LinkedList;import java.util.Queue;import java.util.Scanner;import java.util.Vector;public class Main {static Scanner scan = new Scanner(System.in);static String dirs = "NESW";static String turns = "FLR";static boolean[][][][] has_edge = new boolean[10][10][4][3];static Node[][][] p = new Node[10][10][4];static int[][][] d = new int[10][10][4];static int[] dr = {-1,0,1,0};static int[] dc = {0,1,0,-1};static int r1,c1,dir,r2,c2,r0,c0;/** * @param args */public static void main(String[] args) {// TODO Auto-generated method stubwhile(input()){slove();}}//输入public static boolean input(){for(int i=1;i<=9;i++){for(int j=1;j<=9;j++){for(int k=0;k<4;k++){for(int l=0;l<3;l++){has_edge[i][j][k][l] = false;}}}}String name = scan.next();if("END".equals(name))return false;r0 = scan.nextInt();c0 = scan.nextInt();char c = scan.next().charAt(0);r2 = scan.nextInt();c2 = scan.nextInt();dir = dir_id(c);r1 = r0 + dr[dir];c1 = c0 + dc[dir];while(true){int x = scan.nextInt();if(x==0)break;int y = scan.nextInt();while(true){String str = scan.next();if(str.charAt(0)=='*')break;int dd = dir_id(str.charAt(0));for(int i=1;i<str.length();i++){has_edge[x][y][dd][turn_id(str.charAt(i))] = true;}}}System.out.println(name);return true;}//将方向转化为数字public static int dir_id(char c){return dirs.indexOf(c);}//将转向转化为数字public static int turn_id(char c){return turns.indexOf(c);}//判断坐标是否合法public static boolean inSide(int x,int y){return x>0&&x<=9&&y>0&&y<=9;}//BFSpublic static void slove(){Queue<Node> q = new LinkedList<>();for(int i=1;i<=9;i++){for(int j=1;j<=9;j++){for(int k=0;k<4;k++){d[i][j][k] = -1;}}}//System.out.println(r2+","+c2+","+dir);Node u = new Node(r1,c1,dir);d[u.r][u.c][u.dir] = 0;q.add(u);while(!q.isEmpty()){u = q.poll();if(u.r==r2&&u.c==c2){print_ans(u);return;}for(int i=0;i<3;i++){Node v = walk(u,i);if(has_edge[u.r][u.c][u.dir][i]&&inSide(v.r,v.c)&&d[v.r][v.c][v.dir]<0){d[v.r][v.c][v.dir] = d[u.r][u.c][u.dir]+1;p[v.r][v.c][v.dir] = u;q.add(v);}}}System.out.println("  No Solution Possible");}//控制下一步的方向private static Node walk(Node u, int turn) {int dir = u.dir;if(turn == 1){//逆时针dir =(dir+3)%4;}if(turn == 2){//顺时针dir = (dir+1)%4;}return new Node(u.r+dr[dir],u.c+dc[dir],dir);}//输出答案private static void print_ans(Node u) {Vector<Node> nodes = new Vector<>();for(;;){nodes.add(u);if(d[u.r][u.c][u.dir]==0){break;}u = p[u.r][u.c][u.dir];}nodes.add(new Node(r0,c0,dir));int cnt = 0;for(int i=nodes.size()-1;i>=0;i--){if(cnt%10==0)System.out.print(" ");System.out.printf(" (%d,%d)",nodes.get(i).r,nodes.get(i).c);if(++cnt%10==0)System.out.println();}if(nodes.size()%10!=0){System.out.println();}}//每个节点的信息，包含坐标，和从哪个方向来的static class Node{int r=0,c=0,dir=0;public Node(int r,int c,int dir){this.r = r;this.c = c;this.dir = dir;}}}