LeetCode 965.单值二叉树

把二叉树遍历，然后把每一个数都存入数组，然后再遍历数组即可:

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     struct TreeNode *left;
 *     struct TreeNode *right;
 * };
 */
 void Preorder_trave(struct TreeNode* root,int* number,int* length)
 {
    if(root == NULL)
    {
        return;
    }
    number[(*length)++] = root->val;
    Preorder_trave(root->left,number,length);
    Preorder_trave(root->right,number,length);
 }
bool isUnivalTree(struct TreeNode* root) {
    int* number = (int*)malloc(sizeof(int) * 100);
    int* length = (int*)malloc(sizeof(int));
    *length = 0;
    Preorder_trave(root,number,length);
    int i = 0;
    int k = *length;
    for(i = 0;i < k - 1;i++)
    {
        if(number[i] != number[i + 1])
        {
            return false;
        }
    }
    return true;
}