平衡二叉树实例－－判断输入后序序列是否为平衡二叉树

 1 bool verifyPostorder(vector<int>& postorder){
 2 if(postorder.empty())  return true;
 3 bool res = helper(postorder,0,postorder.sizee()-1);
 4 return res;
 5 }
 6 
 7 bool  helper(vector<int>& postorder,int start,int end){
 8 if(postorder.empty() || start>end)  return false;
 9 
10 int root = postorder[end];
11 int i = start;
12 
13 for(;i<end;i++){
14 if(postorder[i]<root)
15 break;
16 }
17 for(int j = i;j<end;j++){
18 if(postorder[j]<root)
19 return false;
20 }
21 bool left = true;
22 if(i>start)//是否有左子鼠
23 left = helper(postorder,start,i-1);
24 bool right = true;
25 if(i<end-1)//是否有柚子树
26 right = helper(postorder,i,end-1);
27 }