[965] Univalued Binary Tree

令人心情好的題目XD

/**

* Definition for a binary tree node.

* struct TreeNode {

* int val;

* struct TreeNode *left;

* struct TreeNode *right;

* };

*/

bool check(struct TreeNode* root, int val){

if (root== NULL)

return true;

if (root->val != val)

return false;

return (check(root->left,val) && check(root->right,val));

}

bool isUnivalTree(struct TreeNode* root){

return check (root, root->val);

}