Merge pull request #283 from leijunjiang/master

Add ruby solutions for september daily challenge.

September-LeetCoding-Challenge/01-Largest-Time-for-Given-Digits/Largest-Time-for-Given-Digits.rb

@@ -0,0 +1,6 @@
+def largest_time_from_digits(a)
+    out = a.permutation.to_a.map {|e| e.join("").to_i}.sort.select{|elt| elt < 2359 && elt.to_s[-2..-1] .to_i < 60}.last
+
+    return "" if out == nil
+    out.to_s.rjust(4, '0').insert(2, ":")
+end

September-LeetCoding-Challenge/02-Contains-Duplicate-III/Contains-Duplicate-III.rb

@@ -0,0 +1,12 @@
+def contains_nearby_almost_duplicate(nums, k, t)
+    length = nums.length
+    out = false
+    0.upto(length-1) do |i|
+        (i+1).upto([length-1,i+k].min) do |n|
+
+            return true if (nums[n] - nums[i]).abs <= t 
+
+        end
+    end
+    out
+end

September-LeetCoding-Challenge/03-Repeated-Substring-Pattern/Repeated-Substring-Pattern.rb

@@ -0,0 +1,18 @@
+def repeated_substring_pattern(s)
+    out = false
+    length = s.length / 2 
+    0.upto(length) do |n|
+        out =  is_repeated_sub?(s[0..n], s)
+        return out if out == true
+    end
+    out
+
+end
+
+def is_repeated_sub?(sub, string)
+    modulo = string.length % sub.length
+    return false if modulo != 0
+    multiplicator = string.length / sub.length 
+    return false if multiplicator <= 1
+    return (sub * multiplicator) == string
+end

September-LeetCoding-Challenge/04-Partition-Labels/Partition-Labels.rb

@@ -0,0 +1,22 @@
+def partition_labels(s)
+    last_indices = Array.new(26)
+    s.each_char.with_index do |val, index|
+       last_indices[val.ord - "a".ord] = index 
+    end
+    last_indices
+    start = 0
+    finish = 0
+    out = []
+
+    p last_indices
+    0.upto((s.length)-1) do |n|
+        val = s[n]
+        finish = [finish, last_indices[val.ord - "a".ord]].max 
+        if finish == n
+
+          out << finish-start + 1
+          start = finish  + 1
+        end
+    end
+    out
+end

September-LeetCoding-Challenge/05-All-Elements-in-Two-Binary-Search-Trees/All-Elements-in-Two-Binary-Search-Trees.rb

@@ -0,0 +1,46 @@
+def get_all_elements(root1, root2)
+
+    arr_1 = in_order(root1, [])
+    arr_2 = in_order(root2, [])
+    res = []
+
+    len1 = arr_1.length
+    len2 =  arr_2.length
+    index_1 = 0
+    index_2 = 0
+
+    while (index_1 <= (len1 -1)) ||  
+          (index_2 <= (len2 -1))
+
+        if arr_1[index_1].nil? && !arr_2[index_2].nil?
+            res << arr_2[index_2]
+            index_2 += 1
+        elsif !arr_1[index_1].nil? && arr_2[index_2].nil?
+            res << arr_1[index_1]
+            index_1 += 1
+
+        elsif arr_1[index_1] < arr_2[index_2]
+            res <<  arr_1[index_1]
+            index_1 += 1
+
+        else
+             res <<  arr_2[index_2]
+            index_2 += 1
+        end
+
+    end
+
+
+    res
+
+end
+
+def in_order(root, arr)
+   if root.nil?
+       return arr
+   else
+       in_order(root.left, arr)
+       arr << root.val
+       in_order(root.right, arr)
+   end
+end

September-LeetCoding-Challenge/06-Image-Overlap/Image-Overlap.rb

@@ -0,0 +1,37 @@
+def largest_overlap(a, b)
+
+    # c'est une solution que je n'ai pas tout comprise
+    # pk [max_overlaps, shift_count(x, y, a, b)].max  et [max_overlaps, shift_count(x, y, b, a)].max suffisent ??
+    max_overlaps = 0
+
+    len = a.length
+
+    0.upto(len-1) do |y|
+        0.upto(len-1) do |x|
+            max_overlaps = [max_overlaps, shift_count(x, y, a, b)].max
+            max_overlaps = [max_overlaps, shift_count(x, y, b, a)].max
+        end
+    end
+    max_overlaps
+
+end
+
+
+
+def shift_count(x, y, m, r)
+   len = m.length
+   count = 0
+   r_row = 0
+
+    y.upto(len - 1) do |m_row|
+       r_col = 0
+
+            x.upto(len - 1) do |m_col|
+                count += 1 if m[m_row][m_col] == 1 &&  m[m_row][m_col] == r[r_row][r_col]
+                r_col += 1
+            end
+
+        r_row +=1
+    end
+    count
+end

September-LeetCoding-Challenge/07-Word-Pattern/Word-Pattern.rb

@@ -0,0 +1,17 @@
+def word_pattern(pattern, str)
+    arr = str.split
+    return false if pattern.length != arr.length
+    l = pattern.length
+    h = {}
+    out = true
+    0.upto(l-1) do |n|
+
+        if h.key?(pattern[n])
+            return out = false if h[pattern[n]] != arr[n]
+        else
+            return false if h.values.include?(arr[n])
+            h.merge!(pattern[n] => arr[n])
+        end
+    end
+    out
+end

September-LeetCoding-Challenge/08-Sum-of-Root-To-Leaf-Binary-Numbers/Sum-of-Root-To-Leaf-Binary-Numbers.rb

@@ -0,0 +1,16 @@
+def sum_root_to_leaf(root)
+    rec(root, 0)
+end
+
+def rec(root, val)
+    if root.nil?
+        return 0
+    else
+        val = val * 2 + root.val
+        if root.left.nil? && root.right.nil?
+           return val
+        end
+        rec(root.left, val) + rec(root.right, val)
+
+    end
+end

September-LeetCoding-Challenge/09-Compare-Version-Numbers/Compare-Version-Numbers.rb

@@ -0,0 +1,23 @@
+def compare_version(version1, version2)
+    arr1 = version1.split(".")
+    arr2 = version2.split(".")
+
+    len = [arr1.length-1, arr2.length-1].max
+
+    0.upto(len) do |n|
+      if arr1[n].nil? && arr2[n].nil?
+        return 0
+      else
+        a = arr1[n] || "0"
+        b = arr2[n] || "0"
+        if a.to_i > b.to_i
+          return 1
+        elsif a.to_i < b.to_i
+          return -1
+        else
+          next
+        end
+      end
+    end
+
+end

September-LeetCoding-Challenge/10-Bulls-and-Cows/Bulls-and-Cows.rb

@@ -0,0 +1,30 @@
+def get_hint(secret, guess)
+   new_guess = []
+    new_secret = []
+    count_a = 0
+    count_b = 0
+
+    guess.chars.to_a.each_with_index do |val, index|
+        if val == secret[index]
+            count_a += 1
+        else
+            new_guess << val
+            new_secret << secret[index]
+        end
+    end
+
+    new_guess.sort!
+    new_secret.sort!
+    while new_guess != [] && new_secret != []
+        s = new_secret.pop
+        g = new_guess.pop
+        if s == g
+            count_b += 1
+        elsif s.to_i > g.to_i
+            new_guess << g
+        elsif s.to_i < g.to_i
+            new_secret <<s
+        end
+    end
+    count_a.to_s + "A" +  count_b.to_s + "B"
+end

September-LeetCoding-Challenge/11-Maximum-Product-Subarray/Maximum-Product-Subarray.rb

@@ -0,0 +1,16 @@
+def max_product(nums)
+
+    min = []
+    min[0] = nums[0]
+    max = []
+    max[0] = nums[0]
+
+    nums.each_with_index do |val, n|
+
+        next if n == 0
+        min[n] = [val, val * min[n-1], val * max[n-1]].min
+        max[n] = [val, val * min[n-1], val * max[n-1]].max
+
+    end
+    max.max
+end

September-LeetCoding-Challenge/12-Combination-Sum-III/Combination-Sum-III.rb

@@ -0,0 +1,23 @@
+def combination_sum3(k, n)
+    path = []
+    res = []
+    bt(k, n, 1, path, res)
+    res
+
+end
+
+def bt(k, n, s, path, res)
+    if k == 0
+        if n == 0
+            res << path.clone
+            return
+        end
+    end
+
+    s.upto(9) do |i|
+        return if i > n
+        path << i
+        bt(k-1, n-i, i+1, path, res)
+        path.pop
+    end
+end