Tree Traversal Target: 10s
Diameter is the max left_height + right_height at any node. Track global max during DFS.
dia = 0
def h(n):
global dia
if not n: return 0
l, r = h(n.left), h(n.right)
dia = max(dia, l + r)
return 1 + max(l, r)Type it from memory. Go.