這篇文章主要介紹了PHP樹的深度編歷生成迷宮及A*自動尋路算法,實例分析了php實現A*尋路算法的技巧,具有一定參考借鑒價值,需要的朋友可以參考下
本文實例講述了PHP樹的深度編歷生成迷宮及A*自動尋路算法。分享給大家供大家參考。具體分析如下：
有一同事推薦了三思的迷宮算法，看了感覺還不錯，就轉成php
三思的迷宮算法是采用樹的深度遍歷原理，這樣生成的迷宮相當的細，而且死胡同數量相對較少！
任意兩點之間都存在唯一的一條通路。
至於A*尋路算法是最大眾化的一全自動尋路算法
廢話不多說，貼上帶代碼
迷宮生成類：
代碼如下:
class Maze{
// Maze Create
private $_w;
private $_h;
private $_grids;
private $_walkHistory;
private $_walkHistory2;
private $_targetSteps;
// Construct
public function Maze() {
$this->_w = 6;
$this->_h = 6;
$this->_grids = array();
}
// 設置迷宮大小
public function set($width = 6, $height = 6) {
if ( $width > 0 ) $this->_w = $width;
if ( $height > 0 ) $this->_h = $height;
return $this;
}
// 取到迷宮
public function get() {
return $this->_grids;
}
// 生成迷宮
public function create() {
$this->_init();
return $this->_walk(rand(0, count($this->_grids) -1 ));
}
// 獲取死胡同點
public function block($n = 0, $rand = false) {
$l = count($this->_grids);
for( $i = 1; $i < $l; $i++ ) {
$v = $this->_grids[$i];
if ( $v == 1 || $v == 2 || $v == 4 || $v == 8 ) {
$return[] = $i;
}
}
// 隨機取點
if ( $rand ) shuffle($return);
if ( $n == 0 ) return $return;
if ( $n == 1 ) {
return array_pop($return);
} else {
return array_slice($return, 0, $n);
}
}
/**
|---------------------------------------------------------------
| 生成迷宮的系列函數
|---------------------------------------------------------------
*/
private function _walk($startPos) {
$this->_walkHistory = array();
$this->_walkHistory2 = array();
$curPos = $startPos;
while ($this->_getNext0() != -1) {
$curPos = $this->_step($curPos);
if ( $curPos === false ) break;
}
return $this;
}
private function _getTargetSteps($curPos) {
$p = 0;
$a = array();
$p = $curPos - $this->_w;
if ($p > 0 && $this->_grids[$p] === 0 && ! $this->_isRepeating($p)) {
array_push($a, $p);
} else {
array_push($a, -1);
}
$p = $curPos + 1;
if ($p % $this->_w != 0 && $this->_grids[$p] === 0 && ! $this->_isRepeating($p)) {
array_push($a, $p);
} else {
array_push($a, -1);
}
$p = $curPos + $this->_w;
if ($p < count($this->_grids) && $this->_grids[$p] === 0 && ! $this->_isRepeating($p)) {
array_push($a, $p);
} else {
array_push($a, -1);
}
$p = $curPos - 1;
if (($curPos % $this->_w) != 0 && $this->_grids[$p] === 0 && ! $this->_isRepeating($p)) {
array_push($a, $p);
} else {
array_push($a, -1);
}
return $a;
}
private function _noStep() {
$l = count($this->_targetSteps);
for ($i = 0; $i < $l; $i ++) {
if ($this->_targetSteps[$i] != -1) return false;
}
return true;
}
private function _step($curPos) {
$this->_targetSteps = $this->_getTargetSteps($curPos);
if ( $this->_noStep() ) {
if ( count($this->_walkHistory) > 0 ) {
$tmp = array_pop($this->_walkHistory);
} else {
return false;
}
array_push($this->_walkHistory2, $tmp);
return $this->_step($tmp);
}
$r = rand(0, 3);
while ( $this->_targetSteps[$r] == -1) {
$r = rand(0, 3);
}
$nextPos = $this->_targetSteps[$r];
$isCross = false;
if ( $this->_grids[$nextPos] != 0)
$isCross = true;
if ($r == 0) {
$this->_grids[$curPos] ^= 1;
$this->_grids[$nextPos] ^= 4;
} elseif ($r == 1) {
$this->_grids[$curPos] ^= 2;
$this->_grids[$nextPos] ^= 8;
} elseif ($r == 2) {
$this->_grids[$curPos] ^= 4;
$this->_grids[$nextPos] ^= 1;
} elseif ($r == 3) {
$this->_grids[$curPos] ^= 8;
$this->_grids[$nextPos] ^= 2;
}
array_push($this->_walkHistory, $curPos);
return $isCross ? false : $nextPos;
}
private function _isRepeating($p) {
$l = count($this->_walkHistory);
for ($i = 0; $i < $l; $i ++) {
if ($this->_walkHistory[$i] == $p) return true;
}
$l = count($this->_walkHistory2);
for ($i = 0; $i < $l; $i ++) {
if ($this->_walkHistory2[$i] == $p) return true;
}
return false;
}
private function _getNext0() {
$l = count($this->_grids);
for ($i = 0; $i <= $l; $i++ ) {
if ( $this->_grids[$i] == 0) return $i;
}
return -1;
}
private function _init() {
$this->_grids = array();
for ($y = 0; $y < $this->_h; $y ++) {
for ($x = 0; $x < $this->_w; $x ++) {
array_push($this->_grids, 0);
}
}
return $this;
}
}
A*尋路算法
代碼如下:
class AStar{
// A-star
private $_open;
private $_closed;
private $_start;
private $_end;
private $_grids;
private $_w;
private $_h;
// Construct
public function AStar(){
$this->_w = null;
$this->_h = null;
$this->_grids = null;
}
public function set($width, $height, $grids) {
$this->_w = $width;
$this->_h = $height;
$this->_grids = $grids;
return $this;
}
// 迷宮中尋路
public function search($start = false, $end = false) {
return $this->_search($start, $end);
}
/**
|---------------------------------------------------------------
| 自動尋路 - A-star 算法
|---------------------------------------------------------------
*/
public function _search($start = false, $end = false) {
if ( $start !== false ) $this->_start = $start;
if ( $end !== false ) $this->_end = $end;
$_sh = $this->_getH($start);
$point['i'] = $start;
$point['f'] = $_sh;
$point['g'] = 0;
$point['h'] = $_sh;
$point['p'] = null;
$this->_open[] = $point;
$this->_closed[$start] = $point;
while ( 0 < count($this->_open) ) {
$minf = false;
foreach( $this->_open as $key => $maxNode ) {
if ( $minf === false || $minf > $maxNode['f'] ) {
$minIndex = $key;
}
}
$nowNode = $this->_open[$minIndex];
unset($this->_open[$minIndex]);
if ( $nowNode['i'] == $this->_end ) {
$tp = array();
while( $nowNode['p'] !== null ) {
array_unshift($tp, $nowNode['p']);
$nowNode = $this->_closed[$nowNode['p']];
}
array_push($tp, $this->_end);
break;
}
$this->_setPoint($nowNode['i']);
}
$this->_closed = array();
$this->_open = array();
return $tp;
}
private function _setPoint($me) {
$point = $this->_grids[$me];
// 所有可選方向入隊列
if ( $point & 1 ) {
$next = $me - $this->_w;
$this->_checkPoint($me, $next);
}
if ( $point & 2 ) {
$next = $me + 1;
$this->_checkPoint($me, $next);
}
if ( $point & 4 ) {
$next = $me + $this->_w;
$this->_checkPoint($me, $next);
}
if ( $point & 8 ) {
$next = $me - 1;
$this->_checkPoint($me, $next);
}
}
private function _checkPoint($pNode, $next) {
if ( $this->_closed[$next] ) {
$_g = $this->_closed[$pNode]['g'] + $this->_getG($next);
if ( $_g < $check['g'] ) {
$this->_closed[$next]['g'] = $_g;
$this->_closed[$next]['f'] = $this->_closed[$next]['g'] + $this->_closed[$next]['h'];
$this->_closed[$next]['p'] = $pNode;
}
} else {
$point['p'] = $pNode;
$point['h'] = $this->_getH($next);
$point['g'] = $this->_getG($next);
$point['f'] = $point['h'] + $point['g'];
$point['i'] = $next;
$this->_open[] = $point;
$this->_closed[$next] = $point;
}
}
private function _getG($point) {
return abs($this->_start - $point);
}
private function _getH($point) {
return abs($this->_end - $point);
}
}
完整實例代碼點擊此處本站下載。
有需要大家可以直接下demo，看看效果！
希望本文所述對大家的php程序設計有所幫助。
