剑指Offer的学习笔记（C#篇）-- 二叉搜索树的后序遍历序列

class Solution
{
    public bool VerifySquenceOfBST(int[] sequence)
    {
        // write code here
        if(sequence.Length == 0)
        {
        return false;
        }
        return Verify(sequence, 0, sequence.Length-1);
    }
    public bool Verify(int[] sequence, int start, int end)
    {
        int root = sequence[end];
        int i = start;
        for(; i<end; i++)
        {
            if(sequence[i] > root)
            break;
        }
        int j = i;
        for(; j<end; j++)
        {
            if(sequence[j] < root)
            return false;
        }
        bool left = true;
        if(i-1 > start)
        {
            left = Verify(sequence, start, i-1);
        }
        bool right = true;
        if(i < end-1)
        {
            right = Verify(sequence, i, end-1);
        }
        return (left && right);
    }
}