学步园

一个叫ACM的寻宝者找到了一个藏宝图，它根据藏宝图找到了一个迷宫，这是一个很特别的迷宫，迷宫里有N个编过号的门（N<=5)，它们分别被编号为A,B,C,D,E.为了找到宝藏，ACM必须打开门，但是，开门之前必须在迷宫里找到这个打开这个门所需的所有钥匙（每个门都至少有一把钥匙），例如：现在A门有三把钥匙，ACM就必须找全三把钥匙才能打开A门。现在请你编写一个程序来告诉ACM，他能不能顺利的得到宝藏。

输入

输入可能会有多组测试数据（不超过10组）。
每组测试数据的第一行包含了两个整数M,N(1<20)，分别代表了迷宫的行和列。接下来的M每行有N个字符，描述了迷宫的布局。其中每个字符的含义如下：

.表示可以走的路
S:表示ACM的出发点
G表示宝藏的位置
X表示这里有墙，ACM无法进入或者穿过。
A,B,C,D,E表示这里是门，a,b,c,d,e表示对应大写字母的门上的钥匙。
注意ACM只能在迷宫里向上下左右四个方向移动。

最后，输入0 0表示输入结束。

输出

每行输出一个YES表示ACM能找到宝藏，输出NO表示ACM找不到宝藏。

样例输入

4 4 
S.X. 
a.X. 
..XG 
.... 
3 4 
S.Xa 
.aXB 
b.AG 
0 0

样例输出

YES 
NO

来源

POJ月赛改编

上传者

张云聪

思路：

不相关集 

首先是TL掉的：

这个目测的是没有考虑到  可能A类门有多个， 门可能连环， 导致无限等待

package practise;

import
java.awt.Point;

import
java.util.ArrayList;

import
java.util.Scanner;

//TL

public
class FindPiece {

public
static void main(String[] args) {

FindPiece findPiece = new FindPiece();

findPiece.solution();

}

public
void solution() {

Scanner in = new Scanner(System.in);

while
(true) {

int x
= in.nextInt();

int y
= in.nextInt();

if ((x
== 0) && (y == 0)) {

break;

}

if ((x
== 0) || (y == 0)) {

System.out.println("NO");

continue;

}

char[][] map = new char[x + 2][y + 2];

for
(int i = 1; i <= x; i++) {

String
buffer = in.next();

for
(int j = 1; j <= y; j++) {

map[i][j] = buffer.charAt(j - 1);

}

}

for
(int i = 0; i < x + 2; i++) {

map[i][0] = 'X';

map[i][y + 1] = 'X';

}

for
(int i = 0; i < y + 2; i++) {

map[0][i] = 'X';

map[x
+ 1][i] = 'X';

}

UnRelatedSet unRelatedSet = new UnRelatedSet(map, x,
y);

unRelatedSet.sort();

if(unRelatedSet.findPiece()){

System.out.println("YES");

}else{

System.out.println("NO");

}

}

}

class
UnRelatedSet {

char[][] map; // 记录地图

char[]
doorList = { 'A', 'B', 'C', 'D', 'E' };

char[]
keyList = { 'a', 'b', 'c', 'd', 'e' };

int x;
// 记录地图的大小

int
y;

ArrayList blockList; // 记录连通图

KeyCounter keyCounter; // 记录每个门的钥匙数量

ArrayList DoorPosition;

ArrayList KeyAPosition;

ArrayList KeyBPosition;

ArrayList KeyCPosition;

ArrayList KeyDPosition;

ArrayList KeyEPosition;

public
UnRelatedSet(char[][] map, int x, int y) {

this.map = map;

this.x
= x;

this.y
= y;

blockList = new ArrayList();

keyCounter = new KeyCounter();

}

private boolean isDoor(char in) {

for
(int i = 0; i < doorList.length; i++) {

if (in
== doorList[i]) {

return
true;

}

}

return
false;

}

public
void sort() {

DoorPosition = new ArrayList();

KeyAPosition = new ArrayList();

KeyBPosition = new ArrayList();

KeyCPosition = new ArrayList();

KeyDPosition = new ArrayList();

KeyEPosition = new ArrayList();

blockList = new ArrayList();

keyCounter = new KeyCounter();

for
(int i = 1; i <= x; i++) {

for
(int j = 1; j <= y; j++) {

if
(map[i][j] != 'X') {

if
(!isDoor(map[i][j])) {

Point
temp_Point = new Point(i, j);

Block
temp_Block = new Block(temp_Point);

switch
(map[i][j]) {

case
'S':

temp_Block.isSin = true;

break;

case
'G':

temp_Block.isGin = true;

break;

case
'a':

keyCounter.countA++;

temp_Block.key_A++;

KeyAPosition.add(new Point(i, j));

break;

case
'b':

keyCounter.countB++;

temp_Block.key_B++;

KeyBPosition.add(new Point(i, j));

break;

case
'c':

keyCounter.countC++;

temp_Block.key_C++;

KeyCPosition.add(new Point(i, j));

break;

case
'd':

keyCounter.countD++;

temp_Block.key_D++;

KeyDPosition.add(new Point(i, j));

break;

case
'e':

keyCounter.countE++;

temp_Block.key_E++;

KeyEPosition.add(new Point(i, j));

break;

}

for
(int k = 0; k < blockList.size(); k++) {

Block
temp = blockList.get(k);

if
(temp.pointList

.contains(new Point(i - 1, j))

||
temp.pointList.contains(new Point(i,

j -
1))) {

temp_Block.add(temp);

blockList.remove(temp);

k--;

continue;

}

}

blockList.add(temp_Block);

}else{

DoorPosition.add(new Point(i,j));

}

}

}

}

for(int i = 0 ; i< DoorPosition.size() ;
i++){

Point
temp = DoorPosition.get(i);

for(int j = 0 ; j < blockList.size()
;j++){

ArrayList temp_pointList =
blockList.get(j).pointList;

if((temp_pointList.contains(new
Point(temp.x-1,temp.y)))||

(temp_pointList.contains(new
Point(temp.x+1,temp.y)))||

(temp_pointList.contains(new
Point(temp.x,temp.y-1)))||

(temp_pointList.contains(new
Point(temp.x,temp.y+1)))){

if(!blockList.get(j).AccessDoor.contains(map[temp.x][temp.y])){

blockList.get(j).AccessDoor.add(map[temp.x][temp.y]);

}

}

}

}

}

public
 boolean findPiece(){

Block
start_Block = new Block(new Point(-1,-1));

for(int i = 0 ; i < blockList.size();i++){

if(blockList.get(i).isSin){

start_Block = blockList.get(i);

break;

}

}

if(start_Block.isGin){

return
true;

}

for(int j = 0 ; j <
start_Block.AccessDoor.size();j++){

switch(start_Block.AccessDoor.get(j)){

case
'A':

if(start_Block.key_A == keyCounter.countA){

for(int i = 0;i <
DoorPosition.size();i++){

if(map[DoorPosition.get(i).x][DoorPosition.get(i).y] ==
'A'){

map[DoorPosition.get(i).x][DoorPosition.get(i).y]
='.';

}

}

for(int i = 0 ; i < KeyAPosition.size() ;
i++){

map[KeyAPosition.get(i).x][KeyAPosition.get(i).y] =
'.';

}

sort();

return
findPiece();

}

break;

case
'B':

if(start_Block.key_B == keyCounter.countB){

for(int i = 0;i <
DoorPosition.size();i++){

if(map[DoorPosition.get(i).x][DoorPosition.get(i).y] ==
'B'){

map[DoorPosition.get(i).x][DoorPosition.get(i).y]
='.';

}

}

for(int i = 0 ; i < KeyBPosition.size() ;
i++){

map[KeyBPosition.get(i).x][KeyBPosition.get(i).y] =
'.';

}

sort();

return
findPiece();

}

break;

case
'C':

if(start_Block.key_C == keyCounter.countC){

for(int i = 0;i <
DoorPosition.size();i++){

if(map[DoorPosition.get(i).x][DoorPosition.get(i).y] ==
'C'){

map[DoorPosition.get(i).x][DoorPosition.get(i).y]
='.';

}

}

for(int i = 0 ; i < KeyCPosition.size() ;
i++){

map[KeyCPosition.get(i).x][KeyCPosition.get(i).y] =
'.';

}

sort();

return
findPiece();

}

   break;

case
'D':

if(start_Block.key_D == keyCounter.countD){

for(int i = 0;i <
DoorPosition.size();i++){

if(map[DoorPosition.get(i).x][DoorPosition.get(i).y] ==
'D'){

map[DoorPosition.get(i).x][DoorPosition.get(i).y]
='.';

}

}

for(int i = 0 ; i < KeyDPosition.size() ;
i++){

map[KeyDPosition.get(i).x][KeyDPosition.get(i).y] =
'.';

}

sort();

return
findPiece();

}

break;

case
'E':

if(start_Block.key_E == keyCounter.countE){

for(int i = 0;i <
DoorPosition.size();i++){

if(map[DoorPosition.get(i).x][DoorPosition.get(i).y] ==
'E'){

map[DoorPosition.get(i).x][DoorPosition.get(i).y]
='.';

}

}

for(int i = 0 ; i < KeyEPosition.size() ;
i++){

map[KeyEPosition.get(i).x][KeyEPosition.get(i).y] =
'.';

}

sort();

return
findPiece();

}

break;

}

}

return
false;

}

}

//
用于记录不同块的信息

class
Block {

ArrayList pointList; // 记录节点坐标

ArrayList AccessDoor; // 记录链接的门;

int
key_A;

int
key_B;

int
key_C;

int
key_D;

int
key_E;

boolean isSin;

boolean isGin;

public
Block(Point point) {

pointList = new ArrayList();

pointList.add(point);

AccessDoor = new ArrayList();

key_A
= 0;

key_B
= 0;

key_C
= 0;

key_D
= 0;

key_E
= 0;

isSin
= false;

isGin
= false;

}

public
void add(Block block) {

pointList.addAll(block.pointList);

key_A
+= block.key_A;

key_B
+= block.key_B;

key_C
+= block.key_C;

key_D
+= block.key_D;

key_E
+= block.key_E;

isSin
= isSin || block.isSin;

isGin
= isGin || block.isGin;

for(int i = 0 ; i < block.AccessDoor.size()
;i++){

if(!
AccessDoor.contains(block.AccessDoor.get(i))){

AccessDoor.add(block.AccessDoor.get(i));

}

}

}

}

// 用于
记录每个门所需要的钥匙数量

class
KeyCounter {

int
countA;

int
countB;

int
countC;

int
countD;

int
countE;

public
KeyCounter() {

countA
= 0;

countB
= 0;

countC
= 0;

countD
= 0;

countE
= 0;

}

}

}