Merge remote-tracking branch 'upstream/master'

2 files changed, 82 insertions, 10 deletions

diff --git a/challenge-138/abigail/bc/ch-2.bc b/challenge-138/abigail/bc/ch-2.bc
new file mode 100644
index 0000000000..340f9bfea7
--- /dev/null
+++ b/challenge-138/abigail/bc/ch-2.bc
@@ -0,0 +1,30 @@
+#
+# See ../README.md
+#
+
+#
+# Run as: bc ch-2.bc < input-file
+#
+
+define can_split (target, number) {
+    if (target >  number || target < 0) {return 0}
+    if (target == number)               {return 1}
+    pow_10 = 10
+    while (pow_10 <= number) {
+        if (can_split (target - (number % pow_10), number / pow_10)) {
+            return 1
+        }
+        pow_10 *= 10
+    }
+    return 0
+}
+
+
+while (1) {
+    number = read (); if (number == 0) {break}
+    if (can_split (sqrt (number), number)) {
+        1
+    } else {
+        0
+    }
+}
diff --git a/challenge-138/cheok-yin-fung/perl/ch-2.pl b/challenge-138/cheok-yin-fung/perl/ch-2.pl
index 3efbf50fdc..12f10a3e36 100644
--- a/challenge-138/cheok-yin-fung/perl/ch-2.pl
+++ b/challenge-138/cheok-yin-fung/perl/ch-2.pl
@@ -4,10 +4,10 @@
 # Usage: ch-2.pl $N
 use v5.12.0;
 use warnings;
-use List::Util qw/ any sum /;
+use List::Util qw/ any sum all /;
 use Integer::Partition;
 use Algorithm::Combinatorics qw / permutations /;
-use Test::More tests => 3;
+use Test::More tests => 6;
 
 my $NUM = $ARGV[0] || 1;
 
@@ -25,22 +25,29 @@ sub split_number {
     my %wlen;       # hash to record each unordered partition
     return 0 if $N == 1;  #after reading Abigail's code
     my $i = Integer::Partition->new($len);
-    while (my $a = $i->next) {
-        next if any { (length $_) > $upper } @$a; 
+    while (my $len_a = $i->next) {
+        next unless all { $_ <= $upper } @$len_a; 
         # Explanation for above line:
         # It is an optimization.
         # For example, sqrt(9663676416) = 98304
         # so we can expect partitions with $number > 99999,
         # i.e. length $number > 5, 
         # cannot fulfill the requirement.
-        my $j = permutations($a);
+        # (4th public version, 2021-11-15 05:09 GMT)
+
+        # OKAY WITH:::::: next if any { $_ > $upper } @$len_a; 
+        #     (1st public version, 2021-11-14 GMT)
+        # NOT:::::: next if any { length $_ > $upper } @$len_a; 
+        #     (2nd public version, 2021-11-15 04:35 GMT) 
+
+        my $j = permutations($len_a);
         while (my $b = $j->next) {
             if (!defined($wlen{join ",", @$b})) {
                 my @config = ( substr($N ,0, $b->[0]) );
-                my $acc = 0;
+                my $len_acc = 0;
                 for my $k (0..scalar @$b - 2) {
-                    $acc += $b->[$k];
-                    my $temp = substr($N, $acc, $b->[$k+1]);
+                    $len_acc += $b->[$k];
+                    my $temp = substr($N, $len_acc, $b->[$k+1]);
                     $temp =~ s/^[0]*//g;
                     $temp = 0 if $temp eq "";
                     push @config, $temp;
@@ -62,12 +69,16 @@ sub split_number {
 ok split_number(81) == 1, "Example 1";
 ok split_number(9801) == 1, "Example 2";
 ok split_number(36) == 0, "Example 3";
+ok split_number(999*999) == 1, "test case 1 with 10^n-1";
+ok split_number(9999*9999) == 1, "test case 2 with 10^n-1";
+ok split_number(17073424) == 1, "final test";
 
 
-#for fun
-# grep { 1 == split_number($_*$_)} 1..100;
 
 =pod 
+#for fun
+ grep { 1 == split_number($_*$_)} 100..5000;
+
 Output:
 sqrt(81) = 9 = 8 + 1
 sqrt(100) = 10 = 10 + 0
@@ -78,4 +89,35 @@ sqrt(6724) = 82 = 6 + 72 + 4
 sqrt(8281) = 91 = 82 + 8 + 1
 sqrt(9801) = 99 = 98 + 01
 sqrt(10000) = 100 = 100 + 00
+sqrt(55225) = 235 = 5 + 5 + 225
+sqrt(88209) = 297 = 88 + 209
+sqrt(136161) = 369 = 1 + 361 + 6 + 1
+sqrt(136900) = 370 = 1 + 369 + (0)
+sqrt(143641) = 379 = 14 + 364 + 1
+sqrt(171396) = 414 = 17 + 1 + 396
+sqrt(431649) = 657 = 4 + 3 + 1 + 649
+sqrt(455625) = 675 = 45 + 5 + 625
+sqrt(494209) = 703 = 494 + 209
+sqrt(571536) = 756 = 5 + 715 + 36
+sqrt(627264) = 792 = 62 + 726 + 4
+sqrt(826281) = 909 = 826 + 2 + 81
+sqrt(842724) = 918 = 842 + 72 + 4
+sqrt(893025) = 945 = 8 + 930 + 2 + 5
+sqrt(929296) = 964 = 929 + 29 + 6
+sqrt(980100) = 990 = 980 + 10 + (0)
+sqrt(982081) = 991 = 982 + 8 + 1
+sqrt(998001) = 999 = 998 + 1
+sqrt(1000000) = 1000 = 1000 + (0)
+sqrt(1679616) = 1296 = 1 + 679 + 616
+sqrt(2896804) = 1702 = 2 + 896 + 804
+sqrt(3175524) = 1782 = 3 + 1755 + 24
+sqrt(4941729) = 2223 = 494 + 1729
+sqrt(7441984) = 2728 = 744 + 1984
+sqrt(11329956) = 3366 = 11 + 3299 + 56
+sqrt(13293316) = 3646 = 1 + 329 + 3316
+sqrt(13557124) = 3682 = 1 + 3557 + 124
+sqrt(17073424) = 4132 = 1 + 707 + 3424
+sqrt(23804641) = 4879 = 238 + (0) + 4641
+sqrt(24068836) = 4906 = 2 + 4068 + 836
+sqrt(24502500) = 4950 = 2450 + 2500