PHP Quick Sort Small example php quick Sort Implementation method

PHP Quick Sort Small example php quick Sort Implementation method Full code: Set_time_limit (0); function QuickSort ($arr) { if (count ($arr) > 1) {//only if the array length is greater than 1 $k = $arr [0]; The default Reference object is the first object of the array $x = Array (); Smaller than the reference $y = Array (); Larger than the reference $_size = count ($arr); for ($i = 1; $i < $_size; $i + +) { if ($arr [$i] <= $k) { $x [] = $arr [$i]; } else { $y [] = $arr [$i]; } } Recursively arrange the arrays of the two sides separately $x = QuickSort ($x); $y = QuickSort ($y); Return Array_merge ($x, Array ($k), $y); } else { return $arr; } } $test _array = Array (); $n = 0; Test a record of 300,000 records while (+ + $n <=300000) { $test _array[$n] = $n; } Echo ' Array init! '; Shuffle ($test _array); Scramble Order Echo ' Array shuffled '; echo Date (' y-m-d h:m:s '). ' '; $res = QuickSort ($test _array); echo Date (' y-m-d h:m:s '); ?> Copy Code Quick sorting ideas: 1), the target array is divided into two arrays, the default is the first element as the benchmark, 2), if smaller than the reference object is assigned to the left array, otherwise assigned to right;3), according to this method assigned to know that there is only one element in the array.

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