Merge pull request #11049 from E7-87-83/newh

Week 291 Task 1

1 files changed, 27 insertions, 0 deletions

diff --git a/challenge-291/cheok-yin-fung/perl/ch-1.pl b/challenge-291/cheok-yin-fung/perl/ch-1.pl
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+# The Weekly Challenge 291
+# Task 1 Middle Index
+use v5.30;
+use warnings;
+use List::Util qw/sum/;
+
+sub mi {
+    my @arr = $_[0]->@*;
+    my $rsum = (sum @arr) - $arr[0];
+    my $lsum = 0;
+    my $i = 0;
+    while ($lsum != $rsum) {
+        $i++;
+        last if $i > $#arr;
+        $lsum += $arr[$i-1];
+        $rsum = $rsum - $arr[$i];
+        # say ($i," ",$lsum," ",$rsum," ", $lsum+$rsum+$arr[$i]);
+    }
+    return $i if $lsum == $rsum;
+    return -1;
+}
+
+use Test::More tests=>4;
+ok mi([2,3,-1,8,4]) == 3;
+ok mi([1,-1,4]) == 2;
+ok mi([2,5])==-1;
+ok mi([0,2,-1,-1])==0;