剑指Offer（二十三）-- 二叉树搜索树的后序遍历序列

    public boolean VerifySquenceOfBST(int[] sequence) {
        if (sequence == null || sequence.length == 0) {
            return false;
        }
        if (sequence.length == 1) {
            return true;
        }
        return verifySection(sequence, 0, sequence.length - 1);
    }

    private boolean verifySection(int[] sequence, int strat, int end) {
        if (strat >= end) {
            return true;
        }
        int mid = sequence[end];
        int midIndex = end;
        for (int i = strat; i < end; i++) {
            if (sequence[i] > mid) {
                midIndex = i;
                break;
            }
        }
        for (int i = midIndex; i < end; i++) {
            if (sequence[i] < mid) {
                return false;
            }
        }
        // 分别判断前面一部分和后面一部分
        return verifySection(sequence, strat, midIndex - 1) && verifySection(sequence, midIndex, end - 1);
    }