Fix syntax issues

dynamic_programming/coin_change.rb

@@ -1,30 +1,31 @@
 def coin_change_minimum(coins, amount)
-    dp = Array.new(amount+1,-1)
+  dp = Array.new(amount + 1, -1)
-    dp[0] = 0
+  dp[0] = 0
 
-    coins.each do |coin|
+  coins.each do |coin|
-      (coin..amount).each do |i|
+    (coin..amount).each do |i|
-        if dp[i-coin] != -1
+      if dp[i - coin] != -1
-          dp[i] = -1 == dp[i] ? dp[i-coin]+1  : [dp[i],dp[i-coin]+1].min
+        dp[i] = -1 == dp[i] ? dp[i - coin] + 1 : [dp[i], dp[i - coin] + 1].min
-        end
       end
     end
-      
-    dp[amount]
   end
 
-  def coin_change_combinations(coins, amount)
+  dp[amount]
-    dp = Array.new(coins.length+1) { Array.new(amount+1,0) }
+end
-    dp[0][0] = 1
+
-    (1..coins.length).each do |i|
+def coin_change_combinations(coins, amount)
-      (0..amount).each do |j|
+  dp = Array.new(coins.length + 1) { Array.new(amount + 1, 0) }
-          dp[i][j] = dp[i-1][j] + (j < coins[i-1] ? 0 : dp[i][j-coins[i-1]])
+  dp[0][0] = 1
-      end
+  (1..coins.length).each do |i|
+    (0..amount).each do |j|
+      dp[i][j] = dp[i - 1][j] + (j < coins[i - 1] ? 0 : dp[i][j - coins[i - 1]])
     end
-    dp[coins.length][amount]
   end
+  dp[coins.length][amount]
+end
 
-  coins = Array[2,4,5]
+coins = Array[2, 4, 5]
-  amount = 12
+amount = 12
-  puts "Number of combinations of getting change for " + amount.to_s + " is "+ coin_change_combinations(coins, amount).to_s + "."
+puts 'Number of combinations of getting change for ' + amount.to_s + ' is ' + coin_change_combinations(coins,
-  puts "Minimum number of coins required for " + amount.to_s + " is "+ coin_change_minimum(coins, amount).to_s + "."
+                                                                                                       amount).to_s + '.'
+puts 'Minimum number of coins required for ' + amount.to_s + ' is ' + coin_change_minimum(coins, amount).to_s + '.'

maths/decimal_to_binary.rb

@@ -34,9 +34,7 @@ def decimal_to_binary(d)
   return binary if d == 0
   return 1.to_s if d == 1
 
-  binary = decimal_to_binary(d / 2).to_s + binary
+  decimal_to_binary(d / 2).to_s + binary
-
-  binary
 end
 
 puts 'Binary value of 4 is ' + decimal_to_binary(4).to_s