【LeetCode 111】Minimum Depth of Binary Tree

標籤：

方法1：遞迴。

int minDepth(TreeNode* root) {    if (root == NULL)        return 0;    if (root->left == NULL) {        return minDepth(root->right) + 1;    } else if (root->right == NULL) {        return minDepth(root->left) + 1;    } else {        int left_minDepth = minDepth(root->left);        int right_minDepth = minDepth(root->right);        return left_minDepth < right_minDepth ? left_minDepth + 1 : right_minDepth + 1;    }}

方法2：BFS。

int minDepth(TreeNode *root) {    if (root == NULL)        return 0;    queue<TreeNode*> node_queue;    node_queue.push(root);    int count = 0;    while (!node_queue.empty()) {        int len = node_queue.size();        count++;        for (int i = 0; i < len; ++i) {            TreeNode *nodeTmp = node_queue.front();            node_queue.pop();            if (nodeTmp->left)                node_queue.push(nodeTmp->left);            if (nodeTmp->right)                node_queue.push(nodeTmp->right);            if (nodeTmp->left == NULL && nodeTmp->right == NULL)                return count;        }    }}

 

題目分類：二叉樹的遍曆。

【LeetCode 111】Minimum Depth of Binary Tree