题目：

题解：

#define MAX_NODE_SIZE 10000

int findBottomLeftValue(struct TreeNode* root){
    int ret;
    struct TreeNode** queue = (struct TreeNode **)malloc(sizeof(struct TreeNode) * MAX_NODE_SIZE);
    int head = 0;
    int tail = 0;
    queue[tail++] = root;
    while (head != tail) {
        struct TreeNode *p = queue[head++];
        if (p->right) {
            queue[tail++] = p->right;
        }
        if (p->left) {
            queue[tail++] = p->left;
        }
        ret = p->val;
    }
    free(queue);
    return ret;
}