2024 day 4

Author: invalidusrname

2024/ruby/lib/advent_04_ceres_search.rb

@@ -0,0 +1,214 @@
+class WordSearch
+  attr_reader :data, :word
+
+  def initialize(data, word = "XMAS")
+    @data = data
+    @word = word
+  end
+
+  def in_bounds?(row, col)
+    row.between?(0, data.length - 1) && col.between?(0, data[row].length - 1)
+  end
+
+  def count_at(row, col)
+    count = 0
+    count += 1 if horizontal?(row, col)
+    count += 1 if vertical?(row, col)
+    count += diagonal_count_at(row, col)
+    count
+  end
+
+  def horizontal_word(row, col)
+    first = col
+    last = col + word.length - 1
+
+    return "" unless in_bounds?(first, last)
+
+    data[row][first..last] * ''
+  end
+
+  def horizontal?(row, col)
+    match?(horizontal_word(row, col))
+  end
+
+  def vertical_word(row, col)
+    first = row
+    last = row + word.length - 1
+
+    return "" unless in_bounds?(first, last)
+
+    str = ""
+
+    data.each_index do |r|
+      data[r].each_index do |c|
+        str << data[r][c] if col == c && r.between?(first, last)
+      end
+    end
+
+    str
+  end
+
+  def vertical?(row, col)
+    match?(vertical_word(row, col))
+  end
+
+  def diagonal_top_left_word(row, col)
+    str = ""
+
+    (0..word.length - 1).each do |pos|
+      new_row = row - pos
+      new_col = col - pos
+
+      return str unless in_bounds?(new_row, new_col)
+
+      str += data[new_row][new_col]
+    end
+
+    str
+  end
+
+  def diagonal_top_right_word(row, col)
+    str = ""
+
+    (0..word.length - 1).each do |pos|
+      new_row = row - pos
+      new_col = col + pos
+
+      return str unless in_bounds?(new_row, new_col)
+
+      str += data[new_row][new_col]
+    end
+
+    str
+  end
+
+  def letter_at(row, col)
+    in_bounds?(row, col) ? data[row][col] : ""
+  end
+
+  def diagonal_bottom_right_word(row, col)
+    str = ""
+
+    (0..word.length - 1).each do |pos|
+      new_row = row + pos
+      new_col = col + pos
+
+      return str unless in_bounds?(new_row, new_col)
+
+      str += data[new_row][new_col]
+    end
+
+    str
+  end
+
+  def diagonal_bottom_left_word(row, col)
+    str = ""
+
+    (0..word.length - 1).each do |pos|
+      new_row = row + pos
+      new_col = col - pos
+
+      return str unless in_bounds?(new_row, new_col)
+
+      str += data[new_row][new_col]
+    end
+
+    str
+  end
+
+  def match?(str)
+    [str, str.reverse].any? { |w| w == word }
+  end
+
+  def cross_word_at?(row, col)
+    cross_word = "MAS"
+
+    diag_1 = letter_at(row-1, col-1) + letter_at(row, col) + letter_at(row+1, col+1)
+    diag_2 = letter_at(row+1, col-1) + letter_at(row, col) + letter_at(row-1, col+1)
+
+    diag_1_match = [cross_word, cross_word.reverse].any? { |str| str == diag_1 }
+    diag_2_match = [cross_word, cross_word.reverse].any? { |str| str == diag_2 }
+
+    diag_1_match && diag_2_match
+  end
+
+  def cross_word_count
+    count = 0
+
+    data.each_index do |x|
+      data[x].each_index do |y|
+        count += 1 if cross_word_at?(x, y)
+      end
+    end
+
+    count
+  end
+
+  def word_count
+    count = 0
+
+    data.each_index do |x|
+      data[x].each_index do |y|
+        count += count_at(x, y)
+      end
+    end
+
+    count
+  end
+
+  def vertical_count
+    count = 0
+    data.each_index do |x|
+      data[x].each_index do |y|
+        count += 1 if vertical?(x, y)
+      end
+    end
+
+    count
+  end
+
+  def horizonal_count
+    count = 0
+    data.each_index do |x|
+      data[x].each_index do |y|
+        count += 1 if horizontal?(x, y)
+      end
+    end
+
+    count
+  end
+
+  def diagonal_count_at(row, col)
+    count = 0
+    count += 1 if diagonal_top_right_word(row, col) == word
+    count += 1 if diagonal_top_left_word(row, col) == word
+    count += 1 if diagonal_bottom_right_word(row, col) == word
+    count += 1 if diagonal_bottom_left_word(row, col) == word
+    count
+  end
+
+  def diagonal_count
+    count = 0
+
+    data.each_index do |x|
+      data[x].each_index do |y|
+        count += diagonal_count_at(x, y)
+      end
+    end
+
+    count
+  end
+
+  def log_match(prefix, row, col, check)
+    puts "[#{prefix} MATCH] #{row}, #{col}: #{data[row][col]} [#{check}]"
+  end
+
+  def render
+    data.each_index do |x|
+      data[x].each_index do |y|
+        print " #{data[x][y]} "
+      end
+      puts
+    end
+  end
+end