#!/usr/bin/env perl
#
=head1 Task 2: Odd Matrix

Submitted by: Mohammad Sajid Anwar

You are given row and col, also a list of positions in the matrix.

Write a script to perform action on each location (0-indexed) as provided in
the list and find out the total odd valued cells.

For each location (r, c), do both of the following:

    a) Increment by 1 all the cells on row r.
    b) Increment by 1 all the cells on column c.

=head2 Example 1

    Input: $row = 2, $col = 3, @locations = ([0,1],[1,1])
    Output: 6

    Initial:
    [ 0 0 0 ]
    [ 0 0 0 ]

    Apply [0,1]:
    Increment row 0:
    Before     After
    [ 0 0 0 ]  [ 1 1 1 ]
    [ 0 0 0 ]  [ 0 0 0 ]
    Increment col 1:
    Before     After
    [ 1 1 1 ]  [ 1 2 1 ]
    [ 0 0 0 ]  [ 0 1 0 ]

    Apply [1,1]:
    Increment row 1:
    Before     After
    [ 1 2 1 ]  [ 1 2 1 ]
    [ 0 1 0 ]  [ 1 2 1 ]
    Increment col 1:
    Before     After
    [ 1 2 1 ]  [ 1 3 1 ]
    [ 1 2 1 ]  [ 1 3 1 ]

    Final:
    [ 1 3 1 ]
    [ 1 3 1 ]

=head2 Example 2

    Input: $row = 2, $col = 2, @locations = ([1,1],[0,0])
    Output: 0

    Initial:
    [ 0 0 ]
    [ 0 0 ]

    Apply [1,1]:
    Increment row 1:
    Before    After
    [ 0 0 ]   [ 0 0 ]
    [ 0 0 ]   [ 1 1 ]
    Increment col 1:
    Before    After
    [ 0 0 ]   [ 0 1 ]
    [ 1 1 ]   [ 1 2 ]

    Apply [0,0]:
    Increment row 0:
    Before    After
    [ 0 1 ]   [ 1 2 ]
    [ 1 2 ]   [ 1 2 ]
    Increment col 0:
    Before    After
    [ 1 2 ]   [ 2 2 ]
    [ 1 2 ]   [ 2 2 ]

    Final:
    [ 2 2 ]
    [ 2 2 ]

=head2 Example 3

    Input: $row = 3, $col = 3, @locations = ([0,0],[1,2],[2,1])
    Output: 0

    Initial:
    [ 0 0 0 ]
    [ 0 0 0 ]
    [ 0 0 0 ]

    Apply [0,0]:
    Increment row 0:
    Before     After
    [ 0 0 0 ]  [ 1 1 1 ]
    [ 0 0 0 ]  [ 0 0 0 ]
    [ 0 0 0 ]  [ 0 0 0 ]
    Increment col 0:
    Before     After
    [ 1 1 1 ]  [ 2 1 1 ]
    [ 0 0 0 ]  [ 1 0 0 ]
    [ 0 0 0 ]  [ 1 0 0 ]

    Apply [1,2]:
    Increment row 1:
    Before     After
    [ 2 1 1 ]  [ 2 1 1 ]
    [ 1 0 0 ]  [ 2 1 1 ]
    [ 1 0 0 ]  [ 1 0 0 ]
    Increment col 2:
    Before     After
    [ 2 1 1 ]  [ 2 1 2 ]
    [ 2 1 1 ]  [ 2 1 2 ]
    [ 1 0 0 ]  [ 1 0 1 ]

    Apply [2,1]:
    Increment row 2:
    Before     After
    [ 2 1 2 ]  [ 2 1 2 ]
    [ 2 1 2 ]  [ 2 1 2 ]
    [ 1 0 1 ]  [ 2 1 2 ]
    Increment col 1:
    Before     After
    [ 2 1 2 ]  [ 2 2 2 ]
    [ 2 1 2 ]  [ 2 2 2 ]
    [ 2 1 2 ]  [ 2 2 2 ]

    Final:
    [ 2 2 2 ]
    [ 2 2 2 ]
    [ 2 2 2 ]

=head2 Example 4

    Input: $row = 1, $col = 5, @locations = ([0,2],[0,4])
    Output: 2

    Initial:
    [ 0 0 0 0 0 ]

    Apply [0,2]:
    Increment row 0:
    Before         After
    [ 0 0 0 0 0 ]  [ 1 1 1 1 1 ]
    Increment col 2:
    Before         After
    [ 1 1 1 1 1 ]  [ 1 1 2 1 1 ]

    Apply [0,4]:
    Increment row 0:
    Before         After
    [ 1 1 2 1 1 ]  [ 2 2 3 2 2 ]
    Increment col 4:
    Before         After
    [ 2 2 3 2 2 ]  [ 2 2 3 2 3 ]

    Final:
    [ 2 2 3 2 3 ]

=head2 Example 5

    Input: $row = 4, $col = 2, @locations = ([1,0],[3,1],[2,0],[0,1])
    Output: 8

    Initial:
    [ 0 0 ]
    [ 0 0 ]
    [ 0 0 ]
    [ 0 0 ]

    Apply [1,0]:
    Increment row 1:
    Before     After
    [ 0 0 ]    [ 0 0 ]
    [ 0 0 ]    [ 1 1 ]
    [ 0 0 ]    [ 0 0 ]
    [ 0 0 ]    [ 0 0 ]
    Increment col 0:
    Before     After
    [ 0 0 ]    [ 1 0 ]
    [ 1 1 ]    [ 2 1 ]
    [ 0 0 ]    [ 1 0 ]
    [ 0 0 ]    [ 1 0 ]

    Apply [3,1]:
    Increment row 3:
    Before     After
    [ 1 0 ]    [ 1 0 ]
    [ 2 1 ]    [ 2 1 ]
    [ 1 0 ]    [ 1 0 ]
    [ 1 0 ]    [ 2 1 ]
    Increment col 1:
    Before     After
    [ 1 0 ]    [ 1 1 ]
    [ 2 1 ]    [ 2 2 ]
    [ 1 0 ]    [ 1 1 ]
    [ 2 1 ]    [ 2 2 ]

    Apply [2,0]:
    Increment row 2:
    Before     After
    [ 1 1 ]    [ 1 1 ]
    [ 2 2 ]    [ 2 2 ]
    [ 1 1 ]    [ 2 2 ]
    [ 2 2 ]    [ 2 2 ]
    Increment col 0:
    Before     After
    [ 1 1 ]    [ 2 1 ]
    [ 2 2 ]    [ 3 2 ]
    [ 2 2 ]    [ 3 2 ]
    [ 2 2 ]    [ 3 2 ]

    Apply [0,1]:
    Increment row 0:
    Before     After
    [ 2 1 ]    [ 3 2 ]
    [ 3 2 ]    [ 3 2 ]
    [ 3 2 ]    [ 3 2 ]
    [ 3 2 ]    [ 3 2 ]
    Increment col 1:
    Before     After
    [ 3 2 ]    [ 3 3 ]
    [ 3 2 ]    [ 3 3 ]
    [ 3 2 ]    [ 3 3 ]
    [ 3 2 ]    [ 3 3 ]

    Final:
    [ 3 3 ]
    [ 3 3 ]
    [ 3 3 ]
    [ 3 3 ]

=cut

use strict;
use warnings;
use Test2::V0 -no_srand => 1;
use Data::Dumper;

my $cases = [
    [[2, 3, [[0,1],[1,1]]],             6, "Example 1"],
    [[2, 2, [[1,1],[0,0]]],             0, "Example 2"],
    [[3, 3, [[0,0],[1,2],[2,1]]],       0, "Example 3"],
    [[1, 5, [[0,2],[0,4]]],             2, "Example 4"],
    [[4, 2, [[1,0],[3,1],[2,0],[0,1]]], 8, "Example 5"],
];

sub odd_matrix
{
    my ($r, $c, $loc) = @{shift()};

    my @matrix;

    for my $i (0 .. $r-1) {
        for my $j (0 .. $c-1) {
            $matrix[$i][$j] = 0;
        }
    }
    for my $l (@$loc) {
        my ($rr, $cc) = @$l;
        for my $i (0 .. $c-1) {
            $matrix[$rr][$i]++;
        }
        for my $i (0 .. $r-1) {
            $matrix[$i][$cc]++;
        }
    }
    my $odd_count = 0;
    for my $i (0 .. $r-1) {
        for my $j (0 .. $c-1) {
            $odd_count++ if $matrix[$i][$j] % 2;
        }
    }
    return $odd_count;
}

for (@$cases) {
    is(odd_matrix($_->[0]), $_->[1], $_->[2]);
}
done_testing();

exit 0;