https://leetcode.com/problems/binary-tree-tilt/description/
题目:这题其实要你求每个节点的左右子树的差的绝对值,再对这些绝对值求和.
思路:简单递归搜索
class Solution {
public:
int dfs(TreeNode *node)
{
if(node==NULL) return 0;
int l=dfs(node->left);
int r=dfs(node->right);
sum+=abs(l-r);
return l+r-node->val;
}
int findTilt(TreeNode* root) {
sum=0;
dfs(root);
return sum;
}
private:
int sum;
};