[剑指offer][Java]二叉搜索树的后序遍历序列

public class Solution {
    public boolean VerifySquenceOfBST(int [] sequence) {
        if(sequence.length == 0)
            return false;
        if(sequence.length == 1)
            return true;
        return judge(sequence, 0, sequence.length-1);
    }
    private boolean judge(int[] a, int start, int root){
        if(start >= root){
            return true;
        }
        int i = root;
        while(i>start && a[i-1]>a[root])
            i--;// 找到左边最靠右的第一个比root小的数 
        for(int j = start;j<i-1;j++)
            if(a[j]>a[root]) //遍历小于i的，一旦有大于root，说明不满足后序遍历
                return false;
        return judge(a, start, i-1)&&judge(a, i, root-1);
    }
}