Merge pull request #9278 from steve-g-lynn/branch-for-challenge-248

pwc 248

3 files changed, 113 insertions, 0 deletions

diff --git a/challenge-248/steve-g-lynn/blog.txt b/challenge-248/steve-g-lynn/blog.txt
new file mode 100644
index 0000000000..f1e84ab7a3
--- /dev/null
+++ b/challenge-248/steve-g-lynn/blog.txt
@@ -0,0 +1 @@
+https://thiujiac.blogspot.com/2023/12/pwc-248.html
diff --git a/challenge-248/steve-g-lynn/perl/ch-1.pl b/challenge-248/steve-g-lynn/perl/ch-1.pl
new file mode 100755
index 0000000000..16652eeb5a
--- /dev/null
+++ b/challenge-248/steve-g-lynn/perl/ch-1.pl
@@ -0,0 +1,72 @@
+#!/usr/bin/env -S perl -wl
+
+use PDL;
+use Inline Pdlpp;
+
+local *shortest_distance=sub {
+    my ($str,$chr)=@_;
+    ($str =~ /$chr/) || return 0;
+
+    (1==length($chr)) || (die "Single character input needed:$!\n");
+
+    my $retval=zeros(length($str)); #-- pdl to hold return value
+    
+    #-- get indices where the element equals chr
+    my @grp=(grep {$chr eq substr($str,$_,1)} 0..length($str));
+    
+    #-- if the initial matching index is greater than 0 say x, fill 0:x 
+    ($grp[0] > 0) && ($retval->slice("0:$grp[0]") .= sequence($grp[0]+1)->slice('-1:0'));
+    
+    #-- fill in distances between elements of @grp
+    map {
+        $retval->slice("$grp[$_]:$grp[$_+1]") .=
+        pdl($grp[$_])->between(pdl($grp[$_+1]));
+    } 0 .. ($#grp-1);
+    
+    
+    #-- if the last element of @grp is less than the length of $str, fill in the distance for the remaining elemtnts.
+    ($grp[-1] < (length($str)-1)) && ($retval->slice("$grp[-1]:") .= sequence(length($str)-$grp[-1]));
+    
+    return $retval;
+ };
+
+
+print &shortest_distance('loveleetcode','e');
+#[3 2 1 0 1 0 0 1 2 2 1 0]
+
+print &shortest_distance('aaab','b');
+#[3 2 1 0]
+
+__DATA__
+
+__Pdlpp__
+
+pp_def(
+    'between',
+    Pars => 'indx a1(); indx a2(); int [o]b(n);',
+    RedoDimsCode => '$SIZE(n)=$a2()-$a1()+1;',
+    Code => q{
+        PDL_Indx i,c_mid, n_size=$SIZE(n);
+        if (0==(n_size % 2)){
+           c_mid=n_size/2;
+           for (i=0; i < c_mid; i++) {
+                $b(n=>i)=i;             
+           }
+           for (i=c_mid; i < n_size; i++) {
+                $b(n=>i)=n_size-i-1;
+           } 
+        }
+        else {
+            c_mid=(n_size+1)/2;
+            for (i=0; i < c_mid; i++) {
+                $b(n=>i)=i;             
+           }
+           for (i=c_mid; i < n_size; i++) {
+                $b(n=>i)=n_size-i-1;
+           }         
+        }
+    },
+);
+
+
+
diff --git a/challenge-248/steve-g-lynn/perl/ch-2.pl b/challenge-248/steve-g-lynn/perl/ch-2.pl
new file mode 100755
index 0000000000..0c2a7c4789
--- /dev/null
+++ b/challenge-248/steve-g-lynn/perl/ch-2.pl
@@ -0,0 +1,40 @@
+#!/usr/bin/env -S  perl -wl
+
+use PDL;
+use Inline Pdlpp;
+
+my $mat=pdl([[1,2,3,4],[5,6,7,8],[9,10,11,12]]); 
+print $mat->submatrix_sum;
+#[
+# [14 18 22]
+# [30 34 38]
+#]
+
+$mat=pdl([[1,0,0,0],[0,1,0,0],[0,0,1,0],[0,0,0,1]]); 
+print $mat->submatrix_sum;
+#[
+# [2 1 0]
+# [1 2 1]
+# [0 1 2]
+#]
+
+__DATA__
+
+__Pdlpp__
+
+pp_def('submatrix_sum',
+    Pars => 'a(m,n); [o]b(p,q);',
+    RedoDimsCode => '$SIZE(p)=$SIZE(m)-1; $SIZE(q)=$SIZE(n)-1;',
+    Code => q{
+        PDL_Indx i, j, m_size, n_size;
+        m_size=$SIZE(m)-1;
+        n_size=$SIZE(n)-1;
+        for (i=0; i < m_size; i++) {
+            for (j=0; j < n_size; j++) {
+                $b(p=>i, q=>j)=
+                $a(m=>i, n=>j)+$a(m=>i+1, n=>j+1)+
+                $a(m=>i, n=>j+1)+$a(m=>i+1, n=>j);
+            }
+        }
+    },
+);