1688. Count of Matches in Tournament and 2264. Largest 3-Same-Digit Number in String

Author: remy727

Diff for: README.md

@@ -391,6 +391,7 @@
 | 1679 | Max Number of K-Sum Pairs | [Ruby](./algorithms/ruby/1679-max-number-of-k-sum-pairs.rb) | Medium |
 | 1680 | Concatenation of Consecutive Binary Numbers | [Ruby](./algorithms/ruby/1680-concatenation-of-consecutive-binary-numbers.rb) | Medium |
 | 1685 | Sum of Absolute Differences in a Sorted Array | [Ruby](./algorithms/ruby/1685-sum-of-absolute-differences-in-a-sorted-array.rb) | Medium |
+| 1688 | Count of Matches in Tournament | [Ruby](./algorithms/ruby/1688-count-of-matches-in-tournament.rb) | Easy |
 | 1697 | Checking Existence of Edge Length Limited Paths | [Ruby](./algorithms/ruby/1697-checking-existence-of-edge-length-limited-paths.rb) | Hard |
 | 1706 | Where Will the Ball Fall | [Ruby](./algorithms/ruby/1706-where-will-the-ball-fall.rb) | Medium |
 | 1721 | Swapping Nodes in a Linked List | [Ruby](./algorithms/ruby/1721-swapping-nodes-in-a-linked-list.rb) | Medium |
@@ -433,6 +434,7 @@
 | 2215 | Find the Difference of Two Arrays | [Ruby](./algorithms/ruby/2215-find-the-difference-of-two-arrays.rb) | Easy |
 | 2218 | Maximum Value of K Coins From Piles | [Ruby](./algorithms/ruby/2218-maximum-value-of-k-coins-from-piles.rb) | Hard |
 | 2251 | Number of Flowers in Full Bloom | [Ruby](./algorithms/ruby/2251-number-of-flowers-in-full-bloom.rb) | Hard |
+| 2264 | Largest 3-Same-Digit Number in String | [Ruby](./algorithms/ruby/2264-largest-3-same-digit-number-in-string.rb) | Easy |
 | 2265 | Count Nodes Equal to Average of Subtree | [Ruby](./algorithms/ruby/2265-count-nodes-equal-to-average-of-subtree.rb) | Medium |
 | 2272 | Substring With Largest Variance | [Ruby](./algorithms/ruby/2272-substring-with-largest-variance.rb) | Hard |
 | 2300 | Successful Pairs of Spells and Potions | [Ruby](./algorithms/ruby/2300-successful-pairs-of-spells-and-potions.rb) | Medium |

Diff for: algorithms/ruby/1688-count-of-matches-in-tournament.rb

@@ -0,0 +1,60 @@
+# frozen_string_literal: true
+
+# 1688. Count of Matches in Tournament
+# Easy
+# https://leetcode.com/problems/count-of-matches-in-tournament
+
+=begin
+You are given an integer n, the number of teams in a tournament that has strange rules:
+* If the current number of teams is even, each team gets paired with another team. A total of n / 2 matches are played, and n / 2 teams advance to the next round.
+* If the current number of teams is odd, one team randomly advances in the tournament, and the rest gets paired. A total of (n - 1) / 2 matches are played, and (n - 1) / 2 + 1 teams advance to the next round.
+Return the number of matches played in the tournament until a winner is decided.
+
+Example 1:
+Input: n = 7
+Output: 6
+Explanation: Details of the tournament:
+- 1st Round: Teams = 7, Matches = 3, and 4 teams advance.
+- 2nd Round: Teams = 4, Matches = 2, and 2 teams advance.
+- 3rd Round: Teams = 2, Matches = 1, and 1 team is declared the winner.
+Total number of matches = 3 + 2 + 1 = 6.
+
+Example 2:
+Input: n = 14
+Output: 13
+Explanation: Details of the tournament:
+- 1st Round: Teams = 14, Matches = 7, and 7 teams advance.
+- 2nd Round: Teams = 7, Matches = 3, and 4 teams advance.
+- 3rd Round: Teams = 4, Matches = 2, and 2 teams advance.
+- 4th Round: Teams = 2, Matches = 1, and 1 team is declared the winner.
+Total number of matches = 7 + 3 + 2 + 1 = 13.
+
+Constraints:
+1 <= n <= 200
+=end
+
+# @param {Integer} n
+# @return {Integer}
+def number_of_matches(n)
+  matches = 0
+  teams_advancing = n
+
+  while teams_advancing > 1 do
+    matches += teams_advancing / 2
+    teams_advancing = (teams_advancing / 2.0).ceil
+  end
+
+  matches
+end
+
+# **************** #
+#       TEST       #
+# **************** #
+
+require "test/unit"
+class Test_number_of_matches < Test::Unit::TestCase
+  def test_
+    assert_equal 6, number_of_matches(7)
+    assert_equal 13, number_of_matches(14)
+  end
+end

Diff for: algorithms/ruby/2264-largest-3-same-digit-number-in-string.rb

@@ -0,0 +1,72 @@
+# frozen_string_literal: true
+
+# 2264. Largest 3-Same-Digit Number in String
+# Easy
+# https://leetcode.com/problems/largest-3-same-digit-number-in-string
+
+=begin
+You are given a string num representing a large integer. An integer is good if it meets the following conditions:
+* It is a substring of num with length 3.
+* It consists of only one unique digit.
+Return the maximum good integer as a string or an empty string "" if no such integer exists.
+
+Note:
+* A substring is a contiguous sequence of characters within a string.
+* There may be leading zeroes in num or a good integer.
+
+Example 1:
+Input: num = "6777133339"
+Output: "777"
+Explanation: There are two distinct good integers: "777" and "333".
+"777" is the largest, so we return "777".
+
+Example 2:
+Input: num = "2300019"
+Output: "000"
+Explanation: "000" is the only good integer.
+
+Example 3:
+Input: num = "42352338"
+Output: ""
+Explanation: No substring of length 3 consists of only one unique digit. Therefore, there are no good integers.
+
+Constraints:
+3 <= num.length <= 1000
+num only consists of digits.
+=end
+
+# @param {String} num
+# @return {String}
+def largest_good_integer(num)
+  res = []
+  ans = ""
+
+  for i in(0).upto(num.size - 1)
+    if res.empty?
+      res << num[i]
+    elsif res[-1] != num[i]
+      res = [num[i]]
+    else
+      res << num[i]
+    end
+
+    if res.size >= 3 && (ans[-1].to_i <= res[-1].to_i)
+      ans = res[0..2].join
+    end
+  end
+
+  ans
+end
+
+# **************** #
+#       TEST       #
+# **************** #
+
+require "test/unit"
+class Test_largest_good_integer < Test::Unit::TestCase
+  def test_
+    assert_equal "777", largest_good_integer("6777133339")
+    assert_equal "000", largest_good_integer("2300019")
+    assert_equal "", largest_good_integer("42352338")
+  end
+end