DSA/C++/LeetCode/0102.cpp at main · spycedcoffee/DSA · GitHub

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/**
 * 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:
    vector<vector<int>> result;

    void bfs(TreeNode* root){

        if(!root)
            return;

        queue<TreeNode*> q;

        q.push(root);

        vector<int> temp;

        while(!q.empty()){

            temp.clear();

            int siz = q.size();

            while(siz--){

                TreeNode* elem = q.front();
                q.pop();

                temp.push_back(elem -> val);

                if(elem -> left)
                    q.push(elem -> left);

                if(elem -> right)
                    q.push(elem -> right);
            }

            result.push_back(temp);
        }
    }

    vector<vector<int>> levelOrder(TreeNode* root) {

        bfs(root);

        return result;
    }
};