private function _mapKeyIndex($arr,$keys)
    {
        $maps = array();
        foreach ($arr as $index=>$row) {
            $key = "n";
            foreach ($keys as $cName) {
                $key.=$row[$cName];
            }
            if (!isset($maps[$key])) {
                $maps[$key] = array();
            }
            array_push($maps[$key], $index);
        }
        return $maps;
    }
private function _mapKeyIndex($arr,$keys)
    {
        $maps = array();
        foreach ($arr as $index=>$row) {
            $key = "n";
            foreach ($keys as $cName) {
                $key.=$row[$cName];
            }
            if (!isset($maps[$key])) {
                $maps[$key] = array();
            }
            array_push($maps[$key], $index);
        }
        return $maps;
    }
private function _mapKeyIndex ( $ arr , $ keys ) { $ maps = array ( ) ; foreach ( $ arr as $ index => $ row ) { $ key = "n" ; foreach ( $ keys as $ cName ) { $ key .= $ row [ $ cName ] ; } if ( ! isset ( $ maps [ $ key ] ) ) { $ maps [ $ key ] = array ( ) ; } array_push ( $ maps [ $ key ] , $ index ) ; } return $ maps ; }
Map Key Index

@param array $arr  Array to map
@param array $keys List of keys

@return array Return new map
Map Key Index