binary_search

binary_search.pl

#!/usr/bin/env perl

use strict;
use warnings;
use feature 'say';

use DDP { deparse => 1 };

my @seeds;
for (1..100){
    push(@seeds, int(rand(100)));
}
my %hash;
my @array = grep{!$hash{$_}++}@seeds;
@array = sort {$a <=> $b} @array;
p @array;
my ($s, $e) = (0, scalar @array - 1);
my $target = 23;
my $size = @array;
my $result;
my $c = 1;
while ($size > 1){
    say "loop: $c,size: $size, s: $s, e: $e";
    my $i = int($size / 2);
    if ($array[$s + $i] == $target){
        $result = $s + $i;
        last;
    } elsif ($array[$s + $i] > $target){
        $e = $s + $i;
    } else{
        $s = $s + $i;
    }
    $size = $e - $s;
    $c++;
}

if ($result){
    say "result : $result";
} else {
    say "$target not incluide.";
}