513. 找树左下角的值C

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     struct TreeNode *left;
 *     struct TreeNode *right;
 * };
 */

int findBottomLeftValue(struct TreeNode* root) {
    if(!root->left&&!root->right) return root->val;
    struct TreeNode* queue[20000];
    int front=0,tail=1,size=1;
    queue[front]=root;
    struct TreeNode* head=root;
    while(size!=0){
        struct TreeNode* temp=queue[front++];
        head=temp;
        size--;
        if(temp->right) {
            queue[tail++]=temp->right;
            size++;
        }
        if(temp->left) {
            queue[tail++]=temp->left;
            size++;
        }
    }
    return head->val;
}

queue!!