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| -rw-r--r-- | challenge-146/james-smith/README.md | 23 |
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diff --git a/challenge-146/james-smith/README.md b/challenge-146/james-smith/README.md index a0c9ed8cc0..5f5f83bebc 100644 --- a/challenge-146/james-smith/README.md +++ b/challenge-146/james-smith/README.md @@ -39,6 +39,29 @@ try the next number. If we find a factor we skip the rest of the loop and go on We stop when we have 10,000 records in the array (as we don't include the prime number 2 in the list - we explicitly exclude even numbers in the list we search over), so the last element is the 10,001st prime. +For those of you that can't follow/don't like using `?:`, `&&` and `||` instead of `if/else`, `if` and +`unless`. This is that block of code mapped out in full. The slight difference is that in the example +above `$c+=2` is done after the main block is executed, and in this case before {so in this case we +start with `$c=3` which increments to `$c=5` at the start of the loop. + +```perl +my @primes = (3); +my $c = 3; +while( @primes < 10000 ) { + $c += 2; + foreach ( @primes ) { + if( $_*$_ > $c ) { + push @primes, $c; + last; + } + unless( $c % $_ ) { + last; + } + } +} +say $primes[-1]; +``` + # Challenge 2 - Curious Fraction Tree ***The tree below is defined by the following rules. For a fraction `a/b` the children are `a/(b+a)` & `(a+b)/b`. Given a node in the tree `n/m` we need to find the pate back up to the root node.*** |