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|
#!/usr/bin/env perl
use strict;
use warnings;
use feature ":all";
no warnings "experimental";
my $tree={
v=>5,
l=>{
v=>4,
l=>{
v=>11,
l=>{
v=>7
},
r=>{
v=>2
}
},
},
r=>{
v=>8,
l=>{
v=>13,
},
r=>{
v=>9,
r=>{
v=>1
}
}
}
};
my $target=$ARGV[0]//22;
my @stack=($tree);
while (@stack) {
given (shift @stack) {
for my $k (qw<l r>) {
if (exists $_->{$k}) {
$_->{$k}{p}=$_;
push @stack, $_->{$k};
}
}
if ((! exists $_->{l}) and (! exists $_->{r})) {
my $p=$_;
my @path;
my $sum=0;
while (defined $p) {
push @path, $p->{v};
$sum+=$p->{v};
$p=$p->{p};
}
if ($sum==$target) {
say join "->", reverse @path;
}
}
}
}
|
