【leetcode】单值二叉树

bool func(struct TreeNode* node,int val)
{
    if (!node) return true;
    if (node->val != val) return false;
    return func(node->left,val) && func(node->right,val);
}
bool isUnivalTree(struct TreeNode* root){
    if (!root) return false;
    int val = root->val;
    return func(root->left,val) && func(root->right,val);
}