[LeetCode] 222.Count Complete Tree Nodes

    

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Count Complete Tree Nodes - LeetCode

思考過程

待補上

結果✅

/**
 * Definition for a binary tree node.
 * class TreeNode {
 *     public $val = null;
 *     public $left = null;
 *     public $right = null;
 *     function __construct($val = 0, $left = null, $right = null) {
 *         $this->val = $val;
 *         $this->left = $left;
 *         $this->right = $right;
 *     }
 * }
 */
class Solution {

    /**
     * @param TreeNode $root
     * @return Integer
     */
    function countNodes($root) {
        
        if ($root === null) {
            return 0;
        }else{
            
            $sum= 1+ $this->countNodes($root->left)+ $this->countNodes($root->right);
            return $sum;
            }
      }
    
      // function countNodes($root) {
      //   return countfuc($root);
      // }
}

參考內容

Simple two lines solution - LeetCode Discuss

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode() : val(0), left(nullptr), right(nullptr) {}
 *     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
 *     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
 * };
 */
class Solution {
public:
    int func(TreeNode *p){
        if(p==NULL){
            return 0;
        }
        else{
            return 1+func(p->left)+func(p->right);
        }
    }
        int countNodes(TreeNode* root) {
        return func(root);
    }
};