标签：blog class c code color int
Given a binary tree, determine if it is height-balanced.
For this problem, a height-balanced binary tree is defined as a binary tree in which the depth of the two subtrees of every node never differ by more than 1.
The key problem is that recursive func should return not only T/F to indicate if subtree is balanced, but also the depth for parent root to decide if left/right has the same depth.
we use the TreeNode->val to store the depth, so an initialize of val is needed at first.
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class
Solution {public: void
ResetTree(TreeNode * root) { if(root == NULL) { return; } root->val = 0; ResetTree(root->left); ResetTree(root->right); } bool
treeSet = false; bool
isBalanced(TreeNode *root) { if(treeSet == false) { ResetTree(root); treeSet = true; } if(root == NULL) return
true; bool
b1 = isBalanced(root->left); bool
b2 = isBalanced(root->right); if(b1 == false
|| b2 == false) { return
false; } int
d1 = 0; int
d2 = 0; if(root->left) { d1 = root->left->val; } if(root->right) { d2 = root->right->val; } if(d1 > d2) { root->val = d1+1; } else { root->val = d2+1; } if((d1-d2)>1 || (d1-d2)<-1) { return
false; } return
true; }}; |
[LeetCode] [Balanced Binary Tree 2012-10-08 ],布布扣,bubuko.com
[LeetCode] [Balanced Binary Tree 2012-10-08 ]
标签：blog class c code color int
原文地址：http://www.cnblogs.com/xxiao1119/p/3731685.html
