Level Order Traversal

An interactive, step-by-step visualisation of Level Order Traversal.

Category
Trees
Time complexity
O(n)
Space complexity
O(n)

Pseudocode

queue ← [root]
while queue: pop front, visit, enqueue children

Reference implementation

def level_order(root):
    q = deque([root]); out = []
    while q:
        t = q.popleft(); out.append(t.v)
        if t.l: q.append(t.l)
        if t.r: q.append(t.r)
    return out

Open the interactive Level Order Traversal visualisation →