quickSort use two pointers to decrease Time into O(n * lgn ) or O(n)

Quicksort, 选取pivot, 然后有两个指针， left = 0, right = n - 1, left 不停右移找到nums[left] > pivot, right 不停左移找到nums[right] <= pivot直到left >= right, 停止，那么这时候再recursive nums[0: left] and nums[left:] 即可最后sort所有的数值

应用：

[LeetCode] 75. Sort Colors_Medium tag: Two pointers

标签：use,right,lgn,nums,pointers,不停,pivot,left
来源： https://www.cnblogs.com/Johnsonxiong/p/14942987.html