In Perl we frown on the old C style for loop because almost always there is a better way to do it with a Perl foreach style loop. However, not always. The iterator variant below uses a C style loop to remember the last column and last row dealt with to allow a simple last to short circuit the loops with the state of the loop counter propagating the success or failure.

my $i;

for ($i = 0; $i < @array; ++$i) {
    my $row = $array[$i];
    my $j;

    for ($j = 0; $j < @$row; ++$j) {
        last if $row->[$j];
    }

    last if $j == @$row;
}

print "All zero row at $i\n" if $i != @array;

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Given CountZero's test matrix prints:

All zero row at 3

[download]
True laziness is hard work

In reply to Re: An exploration of higher-level-language approaches to the "First all-zero row in an NxN matrix" problem (goto Considered Harmful) by GrandFather
in thread An exploration of higher-level-language approaches to the "First all-zero row in an NxN matrix" problem (goto Considered Harmful) by davido

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