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Tree traversal: Difference between revisions

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Tree traversal (view source)

Revision as of 13:36, 1 December 2022

107 bytes removed ,  1 year ago
→‎{{header|Lua}}: simpler, easier to understand
m (fix markup)
(→‎{{header|Lua}}: simpler, easier to understand)
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=={{header|Lua}}==
<syntaxhighlight lang="lua">-- Utility
local function appenddepth_first(t1tr, t2a, b, c, flat_list)
for _, vval in ipairs(t2{a, b, c}) do
if type(tr[val]) == "table" then
table.insert(t1, v)▼
depth_first(tr[val], a, b, c, flat_list)
end▼
elseif type(tr[val]) ~= "nil" then
table.insert(queueflat_list, nodetr[2val])▼
end -- if
end -- for
return flat_list
end
local function flatten_pre_order(tr) return depth_first(tr, 1, 2, 3, {}) end
local function flatten_in_order(tr) return depth_first(tr, 2, 1, 3, {}) end
local function flatten_post_order(tr) return depth_first(tr, 2, 3, 1, {}) end
 
local function flatten_level_order(tr)
-- Node class
local Nodeflat_list, queue = {}, {tr}
while next(queue) do -- while queue is not empty▼
Node.__index = Node
local node = table.remove(queue, 1) -- dequeue▼
 
if type(node) == "table" then
function Node:order(order)
table.insert(levelorderflat_list, node[1])▼
local r = {}
table.insert(queue, node[32]) -- enqueue▼
append(r, type(self[order[1]]) == "table" and self[order[1]]:order(order) or {self[order[1]]})
table.insert(queue, node[3]) -- enqueue
append(r, type(self[order[2]]) == "table" and self[order[2]]:order(order) or {self[order[2]]})
else
append(r, type(self[order[3]]) == "table" and self[order[3]]:order(order) or {self[order[3]]})
▲ table.insert(t1flat_list, vnode)
return r▼
end -- if
▲ end -- while
 
▲ return rflat_list
function Node:levelorder()
local levelorder = {}
local queue = {self}
▲ while next(queue) do
▲ local node = table.remove(queue, 1)
▲ table.insert(levelorder, node[1])
▲ table.insert(queue, node[2])
▲ table.insert(queue, node[3])
end
return levelorder
end
 
-- Node creator
local function new(value, left, right)
return value and setmetatable({
value,
(type(left) == "table") and new(unpack(left)) or new(left),
(type(right) == "table") and new(unpack(right)) or new(right),
}, Node) or nil
end
 
-- Example
local tree = new({1, {2, {4, 7}, 5}, {3, {6, 8, 9}})}
print("preorderPre order: " .. table.concat(flatten_pre_order(tree:order({1, 2, 3}), " "))
print("inorderIn order: " .. table.concat(flatten_in_order(tree:order({2, 1, 3}), " "))
print("postorderPost order: " .. table.concat(flatten_post_order(tree:order({2, 3, 1}), " "))
print("level-Level order: " .. table.concat(tree:levelorderflatten_level_order(tree), " "))</syntaxhighlight>
</syntaxhighlight>
 
=={{header|M2000 Interpreter}}==
Greagle
27

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