# binary-trees Julia #3 program

## source code

```# The Computer Language Benchmarks Game
# https://salsa.debian.org/benchmarksgame-team/benchmarksgame/
#
# Contributed by Joonas Muhonen. Based on code by Adam Beckmeyer, Jarret Revels, Alex
# Arslan, Michal Stransky, Jens Adam.

struct Node
l::Union{Node,Nothing}
r::Union{Node,Nothing}
end

mutable struct Latch
count::Int
end

function Latch(n::Int)::Latch
end

function countDown(latch::Latch)
lock(latch.cond) do
latch.count -= 1
notify(latch.cond)
end
end

function await(latch::Latch)
lock(latch.cond)
try
while latch.count != 0
wait(latch.cond)
end
finally
unlock(latch.cond)
end
end

function make(n::Int)::Node
n === 0 ? Node(nothing, nothing) : Node(make(n-1), make(n-1))
end

function check(node::Node)::Int
node.l === nothing ? 1 : 1 + check(node.l) + check(node.r)
end

function binary_trees(io, n::Int)
write(io, "stretch tree of depth \$(n+1)\t check: \$(check(make(n+1)))\n")

long_tree::Node = make(n)

minDepth::Int = 4
resultSize::Int = trunc(Int,(n - minDepth) / 2 ) + 1
results = Vector{String}(undef,resultSize)
latch::Latch = Latch(resultSize)
c::Int = 0
niter::Int = 1 << (n - depth + minDepth)
lk::ReentrantLock = ReentrantLock()
lock(lk) do
c+=check(make(depth))
end
end#for
index::Int = trunc(Int,(depth - minDepth)/2) + 1
results[index] = "\$niter\t trees of depth \$depth\t check: \$c\n"
countDown(latch)
end
await(latch)
for i in results
write(io,i)
end

write(io, "long lived tree of depth \$n\t check: \$(check(long_tree))\n")
end#function

isinteractive() || binary_trees(stdout, parse(Int, ARGS[1]))
```

## notes, command-line, and program output

```NOTES:
julia version build 19.0.1+10-21

Wed, 25 Jan 2023 01:13:58 GMT

MAKE:
4

0.11s to complete and log all make actions

COMMAND LINE:
/opt/src/julia-1.8.5/bin/julia -O3 --cpu-target=ivybridge --math-mode=ieee  -- binarytrees.julia-3.julia 21

PROGRAM OUTPUT:
stretch tree of depth 22	 check: 8388607
2097152	 trees of depth 4	 check: 65011712
524288	 trees of depth 6	 check: 66584576
131072	 trees of depth 8	 check: 66977792
32768	 trees of depth 10	 check: 67076096
8192	 trees of depth 12	 check: 67100672
2048	 trees of depth 14	 check: 67106816
512	 trees of depth 16	 check: 67108352
128	 trees of depth 18	 check: 67108736
32	 trees of depth 20	 check: 67108832
long lived tree of depth 21	 check: 4194303
```