Steward

分享是一種喜悅、更是一種幸福

程式語言 - LeetCode - C++ - 513. Find Bottom Left Tree Value

---

題目：


解答：

/**
 * 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 findBottomLeftValue(TreeNode* root) {
        int ans = 0;
        queue<TreeNode*> q;

        q.push(root);
        while (!q.empty()) {
            int n = q.size();

            for (int i = 0; i < n; ++i) {
                TreeNode *t = q.front();
                q.pop();

                ans = t->val;

                if (t->right) {
                    q.push(t->right);
                }
                if (t->left) {
                    q.push(t->left);
                }
            }
        }

        return ans;
    }
};