Created
June 21, 2021 12:40
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binary-tree-level-order-traversal
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class Solution { | |
func levelOrder(_ root: TreeNode?) -> [[Int]] { | |
guard let root = root else { return [] } | |
var q = [TreeNode]() | |
var lists = [[Int]]() | |
q.append(root) | |
while !q.isEmpty { | |
lists.append(q.map { $0.val }) | |
print(lists, "list") | |
q = q.reduce([]) { l, t in | |
l + [t.left, t.right] // [] + [2,2] = [2,2] | |
}.compactMap({$0}) | |
} | |
return lists | |
} | |
} | |
var rootTest = TreeNode(3, TreeNode(9), TreeNode(20, TreeNode(15), TreeNode(7))) | |
var tlal = TreeNode(3, TreeNode(2, TreeNode(10), TreeNode(10)), TreeNode(2, TreeNode(10), TreeNode(10))) | |
Solution().levelOrder(tlal) |
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