Using List::Util->sum() and grep seems to work.

knoppix@Microknoppix:~$ perl -MList::Util=sum -E '
> @array = (
>    [ qw{ 1 1 1 1 1 } ],
>    [ qw{ 0 1 1 0 0 } ],
>    [ qw{ 0 0 0 0 1 } ],
>    [ qw{ 0 0 0 0 0 } ],
>    [ qw{ 0 1 0 1 0 } ],
>    [ qw{ 0 0 0 0 0 } ],
>    );
> say qq{First all-zero row is @{ [
>    ( grep { ! sum @{ $array[ $_ ] } } 0 .. $#array )[ 0 ] ] }};'
First all-zero row is 3
knoppix@Microknoppix:~$

[download]

I hope this is of interest.

Update: I'm stupid! It's even simpler to use List::Util->first() instead of grep.

knoppix@Microknoppix:~$ perl -MList::Util=sum,first -E '
> @array = (
>    [ qw{ 1 1 1 1 1 } ],
>    [ qw{ 0 1 1 0 0 } ],
>    [ qw{ 0 0 0 0 1 } ],
>    [ qw{ 0 0 0 0 0 } ],
>    [ qw{ 0 1 0 1 0 } ],
>    [ qw{ 0 0 0 0 0 } ],
>    );
> say q{First all-zero row is },
>    first { ! sum @{ $array[ $_ ] } } 0 .. $#array;'
First all-zero row is 3
knoppix@Microknoppix:~$

[download]

Update 2: Stupid and naive :-( List::Util->sum() is not a good tool as it will fail on something as simple as the new second row below. Using a List::Util->first() within another List::Util->first() might be better.

knoppix@Microknoppix:~$ perl -MList::Util=first -E '
> @array = (
>    [ qw{ 1 1 1 1 1 } ],
>    [ qw{ 1 0 0 -1 0 } ],
>    [ qw{ 0 1 1 0 0 } ],
>    [ qw{ 0 0 0 0 1 } ],
>    [ qw{ 0 0 0 0 0 } ],
>    [ qw{ 0 1 0 1 0 } ],
>    [ qw{ 0 0 0 0 0 } ],
>    );
> 
> $found = first {
>    $i = $_;
>    $res = first {
>       $array[ $i ]->[ $_ ] != 0
>       } 0 .. $#{ $array[ $i ] };
>    ! defined $res;
>    } 0 .. $#array;
> say
>    q{First all-zero row is -> },
>    defined $found
>    ? $found
>    : q{none found};
> '
First all-zero row is -> 4
knoppix@Microknoppix:~$

[download]

Cheers,

JohnGG

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 johngg
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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