The weekly challenge 337 - Task 2: Odd Matrix

  1 #!/usr/bin/env perl
  2 # https://theweeklychallenge.org/blog/perl-weekly-challenge-337/#TASK2
  3 #
  4 # Task 2: Odd Matrix
  5 # ==================
  6 #
  7 # You are given row and col, also a list of positions in the matrix.
  8 #
  9 # Write a script to perform action on each location (0-indexed) as provided in
 10 # the list and find out the total odd valued cells.
 11 #
 12 # For each location (r, c), do both of the following:
 13 #
 14 # a) Increment by 1 all the cells on row r.
 15 # b) Increment by 1 all the cells on column c.
 16 #
 17 #
 18 ## Example 1
 19 ##
 20 ## Input: $row = 2, $col = 3, @locations = ([0,1],[1,1])
 21 ## Output: 6
 22 ##
 23 ## Initial:
 24 ## [ 0 0 0 ]
 25 ## [ 0 0 0 ]
 26 ##
 27 ## Apply [0,1]:
 28 ## Increment row 0:
 29 ## Before     After
 30 ## [ 0 0 0 ]  [ 1 1 1 ]
 31 ## [ 0 0 0 ]  [ 0 0 0 ]
 32 ## Increment col 1:
 33 ## Before     After
 34 ## [ 1 1 1 ]  [ 1 2 1 ]
 35 ## [ 0 0 0 ]  [ 0 1 0 ]
 36 ##
 37 ## Apply [1,1]:
 38 ## Increment row 1:
 39 ## Before     After
 40 ## [ 1 2 1 ]  [ 1 2 1 ]
 41 ## [ 0 1 0 ]  [ 1 2 1 ]
 42 ## Increment col 1:
 43 ## Before     After
 44 ## [ 1 2 1 ]  [ 1 3 1 ]
 45 ## [ 1 2 1 ]  [ 1 3 1 ]
 46 ##
 47 ## Final:
 48 ## [ 1 3 1 ]
 49 ## [ 1 3 1 ]
 50 #
 51 #
 52 ## Example 2
 53 ##
 54 ## Input: $row = 2, $col = 2, @locations = ([1,1],[0,0])
 55 ## Output: 0
 56 ##
 57 ## Initial:
 58 ## [ 0 0 ]
 59 ## [ 0 0 ]
 60 ##
 61 ## Apply [1,1]:
 62 ## Increment row 1:
 63 ## Before    After
 64 ## [ 0 0 ]   [ 0 0 ]
 65 ## [ 0 0 ]   [ 1 1 ]
 66 ## Increment col 1:
 67 ## Before    After
 68 ## [ 0 0 ]   [ 0 1 ]
 69 ## [ 1 1 ]   [ 1 2 ]
 70 ##
 71 ## Apply [0,0]:
 72 ## Increment row 0:
 73 ## Before    After
 74 ## [ 0 1 ]   [ 1 2 ]
 75 ## [ 1 2 ]   [ 1 2 ]
 76 ## Increment col 0:
 77 ## Before    After
 78 ## [ 1 2 ]   [ 2 2 ]
 79 ## [ 1 2 ]   [ 2 2 ]
 80 ##
 81 ## Final:
 82 ## [ 2 2 ]
 83 ## [ 2 2 ]
 84 #
 85 #
 86 ## Example 3
 87 ##
 88 ## Input: $row = 3, $col = 3, @locations = ([0,0],[1,2],[2,1])
 89 ## Output: 0
 90 ##
 91 ## Initial:
 92 ## [ 0 0 0 ]
 93 ## [ 0 0 0 ]
 94 ## [ 0 0 0 ]
 95 ##
 96 ## Apply [0,0]:
 97 ## Increment row 0:
 98 ## Before     After
 99 ## [ 0 0 0 ]  [ 1 1 1 ]
100 ## [ 0 0 0 ]  [ 0 0 0 ]
101 ## [ 0 0 0 ]  [ 0 0 0 ]
102 ## Increment col 0:
103 ## Before     After
104 ## [ 1 1 1 ]  [ 2 1 1 ]
105 ## [ 0 0 0 ]  [ 1 0 0 ]
106 ## [ 0 0 0 ]  [ 1 0 0 ]
107 ##
108 ## Apply [1,2]:
109 ## Increment row 1:
110 ## Before     After
111 ## [ 2 1 1 ]  [ 2 1 1 ]
112 ## [ 1 0 0 ]  [ 2 1 1 ]
113 ## [ 1 0 0 ]  [ 1 0 0 ]
114 ## Increment col 2:
115 ## Before     After
116 ## [ 2 1 1 ]  [ 2 1 2 ]
117 ## [ 2 1 1 ]  [ 2 1 2 ]
118 ## [ 1 0 0 ]  [ 1 0 1 ]
119 ##
120 ## Apply [2,1]:
121 ## Increment row 2:
122 ## Before     After
123 ## [ 2 1 2 ]  [ 2 1 2 ]
124 ## [ 2 1 2 ]  [ 2 1 2 ]
125 ## [ 1 0 1 ]  [ 2 1 2 ]
126 ## Increment col 1:
127 ## Before     After
128 ## [ 2 1 2 ]  [ 2 2 2 ]
129 ## [ 2 1 2 ]  [ 2 2 2 ]
130 ## [ 2 1 2 ]  [ 2 2 2 ]
131 ##
132 ## Final:
133 ## [ 2 2 2 ]
134 ## [ 2 2 2 ]
135 ## [ 2 2 2 ]
136 #
137 #
138 ## Example 4
139 ##
140 ## Input: $row = 1, $col = 5, @locations = ([0,2],[0,4])
141 ## Output: 2
142 ##
143 ## Initial:
144 ## [ 0 0 0 0 0 ]
145 ##
146 ## Apply [0,2]:
147 ## Increment row 0:
148 ## Before         After
149 ## [ 0 0 0 0 0 ]  [ 1 1 1 1 1 ]
150 ## Increment col 2:
151 ## Before         After
152 ## [ 1 1 1 1 1 ]  [ 1 1 2 1 1 ]
153 ##
154 ## Apply [0,4]:
155 ## Increment row 0:
156 ## Before         After
157 ## [ 1 1 2 1 1 ]  [ 2 2 3 2 2 ]
158 ## Increment col 4:
159 ## Before         After
160 ## [ 2 2 3 2 2 ]  [ 2 2 3 2 3 ]
161 ##
162 ## Final:
163 ## [ 2 2 3 2 3 ]
164 #
165 #
166 ## Example 5
167 ##
168 ## Input: $row = 4, $col = 2, @locations = ([1,0],[3,1],[2,0],[0,1])
169 ## Output: 8
170 ##
171 ## Initial:
172 ## [ 0 0 ]
173 ## [ 0 0 ]
174 ## [ 0 0 ]
175 ## [ 0 0 ]
176 ##
177 ## Apply [1,0]:
178 ## Increment row 1:
179 ## Before     After
180 ## [ 0 0 ]    [ 0 0 ]
181 ## [ 0 0 ]    [ 1 1 ]
182 ## [ 0 0 ]    [ 0 0 ]
183 ## [ 0 0 ]    [ 0 0 ]
184 ## Increment col 0:
185 ## Before     After
186 ## [ 0 0 ]    [ 1 0 ]
187 ## [ 1 1 ]    [ 2 1 ]
188 ## [ 0 0 ]    [ 1 0 ]
189 ## [ 0 0 ]    [ 1 0 ]
190 ##
191 ## Apply [3,1]:
192 ## Increment row 3:
193 ## Before     After
194 ## [ 1 0 ]    [ 1 0 ]
195 ## [ 2 1 ]    [ 2 1 ]
196 ## [ 1 0 ]    [ 1 0 ]
197 ## [ 1 0 ]    [ 2 1 ]
198 ## Increment col 1:
199 ## Before     After
200 ## [ 1 0 ]    [ 1 1 ]
201 ## [ 2 1 ]    [ 2 2 ]
202 ## [ 1 0 ]    [ 1 1 ]
203 ## [ 2 1 ]    [ 2 2 ]
204 ##
205 ## Apply [2,0]:
206 ## Increment row 2:
207 ## Before     After
208 ## [ 1 1 ]    [ 1 1 ]
209 ## [ 2 2 ]    [ 2 2 ]
210 ## [ 1 1 ]    [ 2 2 ]
211 ## [ 2 2 ]    [ 2 2 ]
212 ## Increment col 0:
213 ## Before     After
214 ## [ 1 1 ]    [ 2 1 ]
215 ## [ 2 2 ]    [ 3 2 ]
216 ## [ 2 2 ]    [ 3 2 ]
217 ## [ 2 2 ]    [ 3 2 ]
218 ##
219 ## Apply [0,1]:
220 ## Increment row 0:
221 ## Before     After
222 ## [ 2 1 ]    [ 3 2 ]
223 ## [ 3 2 ]    [ 3 2 ]
224 ## [ 3 2 ]    [ 3 2 ]
225 ## [ 3 2 ]    [ 3 2 ]
226 ## Increment col 1:
227 ## Before     After
228 ## [ 3 2 ]    [ 3 3 ]
229 ## [ 3 2 ]    [ 3 3 ]
230 ## [ 3 2 ]    [ 3 3 ]
231 ## [ 3 2 ]    [ 3 3 ]
232 ##
233 ## Final:
234 ## [ 3 3 ]
235 ## [ 3 3 ]
236 ## [ 3 3 ]
237 ## [ 3 3 ]
238 #
239 ############################################################
240 ##
241 ## discussion
242 ##
243 ############################################################
244 #
245 # First, we create the intial Matrix filled with 0's. Then we check
246 # each element of the @locations array: Add 1 to each element of the
247 # corresponding column and row. Then just walk the matrix once, counting
248 # the odd elements.
249 # 
250 
251 use v5.36;
252 
253 odd_matrix(2, 3, [0,1],[1,1]);
254 odd_matrix(2, 2, [1,1],[0,0]);
255 odd_matrix(3, 3, [0,0],[1,2],[2,1]);
256 odd_matrix(1, 5, [0,2],[0,4]);
257 odd_matrix(4, 2, [1,0],[3,1],[2,0],[0,1]);
258 
259 sub odd_matrix($row, $col, @locations) {
260     say "Input: $row, $col, (" . join(", ", map { "[$_->[0],$_->[1]]" } @locations), ")";
261     my $matrix;
262     foreach my $r (0..$row-1) {
263         my $tmp = [];
264         foreach my $c (0..$col-1) {
265             push @$tmp, 0;
266         }
267         push @$matrix, $tmp;
268     }
269     foreach my $loc (@locations) {
270         my ($r, $c) = @$loc;
271         foreach my $col1 (0..scalar(@{$matrix->[0]})-1) {
272             $matrix->[$r]->[$col1]++;
273         }
274         foreach my $row1 (0..scalar(@{$matrix})-1) {
275             $matrix->[$row1]->[$c]++;
276         }
277     }
278     my $output = 0;
279     foreach my $r (0..$row-1) {
280         foreach my $c (0..$col-1) {
281             $output++ if $matrix->[$r]->[$c] % 2;
282         }
283     }
284     say "Output: $output";
285 }
286 
287