1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
|
use v6d;
################################################################################
=begin comment
Perl Weekly Challenge 262
=========================
TASK #2
-------
*Count Equal Divisible*
Submitted by: Mohammad Sajid Anwar
You are given an array of integers, @ints and an integer $k.
Write a script to return the number of pairs (i, j) where
a) 0 <= i < j < size of @ints
b) ints[i] == ints[j]
c) i x j is divisible by k
Example 1
Input: @ints = (3,1,2,2,2,1,3) and $k = 2
Output: 4
(0, 6) => ints[0] == ints[6] and 0 x 6 is divisible by 2
(2, 3) => ints[2] == ints[3] and 2 x 3 is divisible by 2
(2, 4) => ints[2] == ints[4] and 2 x 4 is divisible by 2
(3, 4) => ints[3] == ints[4] and 3 x 4 is divisible by 2
Example 2
Input: @ints = (1,2,3) and $k = 1
Output: 0
=end comment
################################################################################
#--------------------------------------#
# Copyright © 2024 PerlMonk Athanasius #
#--------------------------------------#
#===============================================================================
=begin comment
Assumption
----------
The divisor $k may take any integer value, positive or negative, except zero.
Interface
---------
1. If no command-line arguments are given, the test suite is run. Otherwise:
2. The divisor $k is given on the command-line as a named argument, followed by
a (possibly empty) list of integers.
3. If the first integer in the list (i.e., following $k) on the command-line is
negative, it must be preceded by "--" to indicate that it is not a command-
line flag.
4. If the constant VERBOSE is set to True, the output count is followed by a
list of the (i, j) pairs themselves.
=end comment
#===============================================================================
use Test;
my Bool constant VERBOSE = True;
#-------------------------------------------------------------------------------
BEGIN
#-------------------------------------------------------------------------------
{
"\nChallenge 262, Task #2: Count Equal Divisible (Raku)\n".put;
}
#===============================================================================
multi sub MAIN
(
Int:D :$k where { $k != 0 }, #= The divisor: a non-zero integer
*@ints where { .all ~~ Int:D } #= A list of integers
)
#===============================================================================
{
"Input: \@ints = (%s) and \$k = %d\n".printf: @ints.join( ', ' ), $k;
my Pair @pairs = find-equal-divisible-pairs( @ints, $k );
"Output: %d\n".printf: @pairs.elems;
"\nPairs found: %s\n".printf:
@pairs.map( { '(' ~ .key ~ ', ' ~ .value ~ ')' } ).join( ', ' )
if VERBOSE;
}
#===============================================================================
multi sub MAIN() # No input: run the test suite
#===============================================================================
{
run-tests();
}
#-------------------------------------------------------------------------------
sub find-equal-divisible-pairs
(
List:D[Int:D] $ints,
Int:D $k where { $k != 0 }
--> List:D[Pair:D]
)
#-------------------------------------------------------------------------------
{
my Pair @pairs;
for 0 .. $ints.end - 1 -> UInt $i
{
for $i + 1 .. $ints.end -> UInt $j
{
@pairs.push: $i => $j
if $ints[ $i ] == $ints[ $j ] && ($i * $j) %% $k;
}
}
return @pairs;
}
#-------------------------------------------------------------------------------
sub run-tests()
#-------------------------------------------------------------------------------
{
'Running the test suite'.put;
for test-data.lines -> Str $line
{
my Str ($test-name, $ints-str, $k-str, $expected) =
$line.split: / \| /;
for $test-name, $ints-str, $k-str, $expected
{
s/ ^ \s+ //;
s/ \s+ $ //;
}
my Int @ints = $ints-str.split( / \s+ /, :skip-empty ).map: { .Int };
my Pair @pairs = find-equal-divisible-pairs( @ints, $k-str.Int );
is @pairs.elems, $expected.Int, $test-name;
}
done-testing;
}
#-------------------------------------------------------------------------------
sub error( Str:D $message )
#-------------------------------------------------------------------------------
{
"ERROR: $message".put;
USAGE();
exit 0;
}
#-------------------------------------------------------------------------------
sub USAGE()
#-------------------------------------------------------------------------------
{
my Str $usage = $*USAGE;
$usage ~~ s:g/ ($*PROGRAM-NAME) /raku $0/;
$usage.put;
}
#-------------------------------------------------------------------------------
sub test-data( --> Str:D )
#-------------------------------------------------------------------------------
{
return q:to/END/;
Example 1 | 3 1 2 2 2 1 3| 2|4
Example 2 | 1 2 3 | 1|0
Negative $k 1 | 3 1 2 2 2 1 3|-1|5
Negative $k 2 | 3 1 2 2 2 1 3|-2|4
Negative ints 1|-3 -1 2 -2 -2 -1 -3| 2|2
Negative ints 2|-3 -1 2 -2 -2 -1 -3|-2|2
END
}
################################################################################
|
