diff options
| -rw-r--r-- | challenge-125/cheok-yin-fung/perl/ch-1.pl | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/challenge-125/cheok-yin-fung/perl/ch-1.pl b/challenge-125/cheok-yin-fung/perl/ch-1.pl index 6258feda8a..7a700d2ed0 100644 --- a/challenge-125/cheok-yin-fung/perl/ch-1.pl +++ b/challenge-125/cheok-yin-fung/perl/ch-1.pl @@ -37,6 +37,11 @@ sub pyth ($n) { } } + + # (C+1)^2 - C^2 = 2C + 1 + # 2C + 1 <= n^2 + # C <= (n^2-1)/2 + for my $b0 ($n+1..int ($n*$n-1)/2) { my $is_sq = $b0*$b0 + $n*$n; if (sqrt($is_sq) == int sqrt($is_sq)) { |