From 9091fef736477a14d7f8092e1355bd49d52beac0 Mon Sep 17 00:00:00 2001
From: Fung Cheok Yin <61836418+E7-87-83@users.noreply.github.com>
Date: Tue, 28 Apr 2020 13:56:05 +0800
Subject: Update ch-2.pl

---
 challenge-058/cheok-yin-fung/perl/ch-2.pl | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/challenge-058/cheok-yin-fung/perl/ch-2.pl b/challenge-058/cheok-yin-fung/perl/ch-2.pl
index 3be4ef6dfb..443054141a 100644
--- a/challenge-058/cheok-yin-fung/perl/ch-2.pl
+++ b/challenge-058/cheok-yin-fung/perl/ch-2.pl
@@ -23,7 +23,6 @@ my @H = (27, 21, 37,  4, 19, 52, 23, 64,  1,  7, 51, 17, 24, 50,  3,  2,
 # end: from the question statement
 
 my $N = $#H+1;
-my @inversion_seq;
 
 my %height_appeartime;
 for (1..$N) { $height_appeartime{$_} = $H[$_-1]; }
@@ -43,7 +42,11 @@ for my $i (0..$N-1) {
     for (0..$N-1) {
         push @possible_place, $_ if $placement[$_] == -1;
     }
-    $placement[ $possible_place[ $inversion_seq[$i] ] ] = $i;
+    if ( defined($possible_place[$inversion_seq[$i]]) ) {
+        $pos = $possible_place[ $inversion_seq[$i] ]; 
+    } else {die "ERROR";}
+
+    $placement[ $pos ] = $i;
 }
 
 @placement = map { $_+1 } @placement;
-- 
cgit