#!/usr/bin/perl

use Benchmark;

sub quadratic {     # Compute the larger root of a quadratic polynomial
    my ($a, $b, $c) = @_;
    return (-$b + sqrt($b*$b - 4*$a * $c)) / 2*$a;
}

sub bruteforce {    # Search linearly until we find a good-enough choice
    my ($low, $high) = @_;
    my $x;
    for ($x = $low; $x <= $high; $x += .001) {
        return $x if abs($x * ($x+1) - .999) < .001;
    }
}

timethese(10000, { quadratic  => 'quadratic(1, 1, -1)',
                   bruteforce => 'bruteforce(0, 1)'        });