Easy,
I made three simple changes.
First: start $cnt as $n*$n instead of 1.
Second: change while loop to continue until $cnt is not greater then 0.
Third: decrement $cnt everywhere it was incremented before.
#!/usr/bin/perl -w
use strict;
print "Enter n: ";
chomp(my $n = <>);
my @shiza;
my $firstD = my $secondD = 0;
my $cnt = $n*$n;
my $inc = 1;
while ($cnt > 0) {
while (!$shiza[$firstD][$secondD] && $secondD < $n && $inc == 1) {
$shiza[$firstD][$secondD] = $cnt;
$secondD++ unless($shiza[$firstD][$secondD+1] || ($secondD+1) >=
+ $n);
$cnt--;
}
$firstD++;
while (!$shiza[$firstD][$secondD] && $firstD < $n && $inc == 1) {
$shiza[$firstD][$secondD] = $cnt;
$firstD++ unless($shiza[$firstD+1][$secondD] || ($firstD+1) >= $
+n);
$cnt--;
}
$secondD--;
$inc = 0;
while (!$shiza[$firstD][$secondD] && $secondD >= 0 && $inc == 0) {
$shiza[$firstD][$secondD] = $cnt;
$secondD-- unless($shiza[$firstD][$secondD-1] || ($secondD-1) <
+0);
$cnt--;
}
$firstD--;
while (!$shiza[$firstD][$secondD] && $firstD >= 0 && $inc == 0) {
$shiza[$firstD][$secondD] = $cnt;
$firstD-- unless($shiza[$firstD-1][$secondD] || ($firstD-1) < 0)
+;
$cnt--;
}
$secondD++;
$inc = 1;
}
for (@shiza) {
for (@{$_}) {
print "$_\t" if($_);
}
print "\n";
}