PHP树的深度编历生成迷宫及A*自动寻路算法实例分析

本文实例讲述了PHP树的深度编历生成迷宫及A*自动寻路算法。分享给大家供大家参考。具体分析如下：

有一同事推荐了三思的迷宫算法，看了感觉还不错，就转成PHP 三思的迷宫算法是采用树的深度遍历原理，这样生成的迷宫相当的细，而且死胡同数量相对较少！ 任意两点之间都存在唯一的一条通路。

至于A*寻路算法是最大众化的一全自动寻路算法

废话不多说，贴上带代码

迷宫生成类：

代码如下:

_w = 6; $this->_h = 6; $this->_grids = array(); } // 设置迷宫大小 public function set($width = 6,$height = 6) { if ( $width > 0 ) $this->_w = $width; if ( $height > 0 ) $this->_h = $height; return $this; } // 取到迷宫 public function get() { return $this->_grids; } // 生成迷宫 public function create() { $this->_init(); return $this->_walk(rand(0,count($this->_grids) -1 )); } // 获取死胡同点 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; } } // 随机取点 if ( $rand ) shuffle($return);

if ( $n == 0 ) return $return;

if ( $n == 1 ) {
return array_pop($return);
} else {
return array_slice($return,$n);
}
}
/*
|---------------------------------------------------------------
| 生成迷宫的系列函数
|---------------------------------------------------------------
/
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,-1);
}
$p = $curPos + $this->_w;
if ($p < count($this->_grids) && $this->_grids[$p] === 0 && ! $this->_isRepeating($p)) {
array_push($a,-1);
}
$p = $curPos - 1;
if (($curPos % $this->_w) != 0 && $this->_grids[$p] === 0 && ! $this->_isRepeating($p)) {
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*寻路算法

代码如下:

_w = null; $this->_h = null; $this->_grids = null; } public function set($width,$height,$grids) { $this->_w = $width; $this->_h = $height; $this->_grids = $grids; return $this; } // 迷宫中寻路 public function search($start = false,$end = false) { return $this->_search($start,$end); } /** |--------------------------------------------------------------- | 自动寻路 - A-star 算法 |--------------------------------------------------------------- */ public function _search($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]; // 所有可选方向入队列 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); } }

完整实例代码点击此处。

有需要大家可以直接下demo，看看效果！

希望本文所述对大家的PHP程序设计有所帮助。