快速排序，快速排序演算法

快速排序，快速排序演算法

快速排序（js實現）

function Quicksort(a) {        Qsort(a, 0, a.length - 1);        return   a;    }    function Qsort(a, low, high) {        var pivot;        if (low < high) {            pivot = Partition(a, low, high);            Qsort(a, low, pivot - 1);            Qsort(a, pivot+1, high);        }    }       function Partition(a, low, high) {        var temp;        var pivotKey;        pivotKey = a[low];        while (low < high) {            while (low < high && a[high] >= pivotKey)                high--;            temp = a[high];            a[high] = a[low];            a[low] = temp;            while (low < high && a[low] <= pivotKey)                low++;            temp = a[low];            a[low] = a[high];            a[high] = temp;        }        return low;    }

測試：

 function getRandom() {        var count = 15;        var random;        var a = new Array();        while (count--) {            random = Math.floor(Math.random() * 1000);            a.push(random);        }               return a;    }

結果：

快速排序的演算法思想最好還是看看資料結構的相關書籍吧，我這裡只是簡單的說下。快速排序就是冒泡排序的升級版本，實現思想就是預先設定一個所謂的中間量（piovtkey）,從low和height兩個方嚮往中間走，完成把比piovtkey大的放右邊，小的放左邊。

 function Partition(a, low, high) {        var temp;        var pivotKey;        pivotKey = a[low];        while (low < high) {            while (low < high && a[high] >= pivotKey)                high--;            temp = a[high];            a[high] = a[low];            a[low] = temp;            while (low < high && a[low] <= pivotKey)                low++;            temp = a[low];            a[low] = a[high];            a[high] = temp;        }        return low;    }

然後在遞迴調用.

if (low < high) {            pivot = Partition(a, low, high);            Qsort(a, low, pivot - 1);            Qsort(a, pivot+1, high);        }