513. Find Bottom Left Tree Value

广度优先遍历

class Solution(object):    def findBottomLeftValue(self, root):        """        :type root: TreeNode        :rtype: int        """        queue = collections.deque()        queue.append(root)        while(queue):            root = queue.popleft()            if (root):                if (root.right):                    queue.append(root.right)                if (root.left):                    queue.append(root.left)

class Solution(object):    def finBottomLeftValue(self,root):        queue=[root]        for node in queue:            queue += filter(None,[node.right,node.left])        return node.val