Array:输入一个整数数组，判断该数组是不是某二叉搜索树的后序

public boolean VerifySquenceOfBST(int[] sequence) {
        if (sequence==null||sequence.length==0) {
            return false;
        }
        return isPos(sequence, 0, sequence.length-1);
    }
    public boolean isPos(int[] ary,int start,int end) {
        if (start>end) {
            return true;
        }
        int index = end-1;
        while (index>start&&ary[index]>ary[end]) {
            index--;
        }
        for (int i = start; i < index; i++) {
            if (ary[i]>ary[end]) {
                return false;
            }
        }
        return isPos(ary, start, index)&&isPos(ary, index+1, end-1);
            
    }