Complete VCS prep ruby challenges 1-6 plus Bigger Challenge

combinations.rb

@@ -0,0 +1,10 @@
+def combinations( strings1, strings2)
+	strings1.collect { |string1|
+		strings2.collect { |string2|
+			string1 + string2
+		}
+	}.flatten
+end
+
+p combinations(["on","in"],["to","rope"])
+# ["onto", "onrope", "into", "inrope"]

counting_game.rb

@@ -0,0 +1,13 @@
+def counting_game(num_players, num_count_to)
+	clockwise = true
+	person = 0
+
+	num_count_to.times do |count|
+		puts "Player " + (person+1).to_s + " says " + (count+1).to_s
+		clockwise = !clockwise if (count+1)%7 == 0
+		(count+1)%11 == 0 ? move = 2 : move = 1
+		clockwise ? person = (person+move)%num_players : person = (person-move)%num_players
+	end
+end
+
+counting_game(10, 100)

factorial.rb

@@ -0,0 +1,11 @@
+def factorial(end_number)
+	return 0 if end_number == 0
+	result = 1
+	(1..end_number).each do |num|
+		result *= num
+	end
+	result
+end
+
+puts factorial(5)
+# 120

is_prime.rb

@@ -0,0 +1,21 @@
+$primes = [2]
+
+def is_prime?(number)
+	return false if number < 1
+	return true if $primes.include?(number)
+	return false if $primes[-1] > number
+
+	test_number = $primes[-1]
+	begin
+		test_number += 1
+		next if $primes.any? { |prime| test_number%prime == 0 }
+
+		$primes << test_number 	
+		return true if test_number == number	
+	end while test_number < number 
+
+	return false
+end
+
+p is_prime? 23 # true
+p $primes # [2, 3, 5, 7, 11, 13, 17, 19, 23]

overlap.rb

@@ -0,0 +1,13 @@
+def overlap(rect1, rect2)
+	rect1_unincl_yrange = (rect1[0][0]+1...rect1[1][0])
+	rect1_unincl_xrange = (rect1[0][1]+1...rect1[1][1])
+	if ( rect1_unincl_xrange.include? rect2[0][0] ) || ( rect1_unincl_xrange.include? rect2[1][0] )
+		if ( rect1_unincl_yrange.include? rect2[0][1] ) || ( rect1_unincl_yrange.include? rect2[1][1] ) 
+			return true
+		end
+	end
+	return false
+end
+
+puts overlap( [ [0,0],[3,3] ], [ [1,1],[4,5] ] ) # true
+puts overlap( [ [0,0],[1,4] ], [ [1,1],[3,2] ] ) # false

power.rb

@@ -0,0 +1,10 @@
+def power(base, exponent)
+	result = 1
+	exponent.times do 
+		result *= base
+	end
+	result
+end
+
+puts power(3,4)
+# 81

prime.rb

@@ -0,0 +1,21 @@
+$primes = [2]
+
+def is_prime?(number)
+	return false if number < 1
+	return true if $primes.include?(number)
+	return false if $primes[-1] > number
+
+	test_number = $primes[-1]
+	begin
+		test_number += 1
+		next if $primes.any? { |prime| test_number%prime == 0 }
+
+		$primes << test_number 	
+		return true if test_number == number	
+	end while test_number < number 
+
+	return false
+end
+
+p is_prime? 23 # true
+p $primes # [2, 3, 5, 7, 11, 13, 17, 19, 23]

uniques.rb

@@ -0,0 +1,12 @@
+def uniques(array)
+	uniq_items = []
+	until array.empty?
+		first_element = array.slice!(0)
+		array.delete_if { |el| el == first_element }
+		uniq_items << first_element
+	end
+	uniq_items 
+end
+
+p uniques([1,5,"frog", 2,1,3,"frog"])
+# [1, 5, "frog", 2, 3]