首頁猿問請(qǐng)教一個(gè)php中二維數(shù)組元素組合的算法

請(qǐng)教一個(gè)php中二維數(shù)組元素組合的算法

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收到一只叮咚 2019-04-19 16:29:37

$arr=array(array('a','b','c'),array('c','f'),array('g','z'),array('x','y'));//$arr子集元素長(zhǎng)度可能會(huì)多一些//將$arr的子集元素與$arr其他子集元素兩兩組合或者三三四四組合//子集array('a','b','c')中的元素不需要組合//兩兩組合$newarr=array(array('a','c'),array('a','f'),array('b','c'),array('b','f'),array('c','c'),array('c','f'),……)//三三組合$newarr=array(array('a','c','g'),array('a','f','g'),array('b','c','g'),array('b','f','g'),array('c','c','g'),array('c','f','g'),……)//四四組合$newarr=array(array('a','c','g','x'),array('a','f','g','x'),array('b','c','g','x'),array('b','f','g','x'),array('c','c','g','x'),array('c','f','g','x'),……)用一個(gè)函數(shù)可以實(shí)現(xiàn)嗎？//$arr：原始數(shù)組，$cNum：組合長(zhǎng)度functiongetCombination($arr,$cNum){……}

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慕村9548890

TA貢獻(xiàn)1884條經(jīng)驗(yàn) 獲得超4個(gè)贊

遞歸？$arr=array(array('a','b','c'),array('c','f'),array('g','z'),array('x','y'));//$arr：原始數(shù)組，$cNum：組合長(zhǎng)度functiongetCombination($arr,$cNum){if($cNum===0){returnreturnarray(array('a'),array('b'),array('c'),);}else{$tmpArr2=$arr;$resultArr=array();array_pop($tmpArr2);$lastNewArr=getCombination($tmpArr2,$cNum-1);for($i=0;$ifor($j=0;$j$tmpArr=$lastNewArr[$i];$tmpArr[]=$arr[$cNum][$j];$resultArr[]=$tmpArr;}}return$resultArr;}}print_r(getCombination($arr,count($arr)-1));

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TA貢獻(xiàn)1846條經(jīng)驗(yàn) 獲得超7個(gè)贊

題主的問題應(yīng)該是PHP計(jì)算二維數(shù)組笛卡爾積吧？如果是的話，請(qǐng)看以下代碼：classDescartes{public$sourceArray;public$resultArray;publicfunction__construct($array,$result){$this->sourceArray=$array;$this->resultArray=$result;}publicfunctioncalcDescartes($arrIndex,$arrResult){if($arrIndex>=count($this->sourceArray)){array_push($this->resultArray,$arrResult);return;}$currentArray=$this->sourceArray[$arrIndex];$currentArrayCount=count($currentArray);$arrResultCount=count($arrResult);for($i=0;$i<$currentArrayCount;++$i){$currentArraySlice=array_slice($arrResult,0,$arrResultCount);array_push($currentArraySlice,$currentArray[$i]);$this->calcDescartes($arrIndex+1,$currentArraySlice);}}}$example=[['a','b','c'],['c','f'],['g','z'],['x','y']];$result=[];$descartes=newDescartes($example,$result);$descartes->calcDescartes(0,$result);var_dump($descartes->resultArray);