# while による繰り返し（例�@）
i = 1
while i <= 5 do
  puts( i.to_s + "回目です。" )
  i += 1
end

# while による繰り返し（例�A）
total = 0
i = 1
while i <= 10 do
	total += i
	i += 1
end
puts( total )

# while による繰り返し（例�A'）
total = 0
i = 1
while total <= 100 do
	total += i
	i += 1
end
print( i , " " , total )

# while による繰り返し（例�B）
i = 10
while i != 0 do
	puts( i )
   i -= 1
end

i = 10
while i > 0 do
	puts( i )
   i -= 1
end

# while による繰り返し（例�C）
i = 0
while i < 10 do
	puts( i * 2 )
   i += 1
end

i = 0
while i <=10 do
	puts( i * 2 )
   i += 1
end

# while による繰り返し（例�D）
i = 1000
while i > 0 do
	puts( i )
   i = i / 2
end

i = 2
while i < 100000 do
	puts( i )
   i = i * 2
end

# while による繰り返し（例�E）
i = 1
while i <= 5 do
  puts( i.to_s + "回目です。" )
end

# times と while の違い�B
i = 2
while i < 100000 do
	puts( i )
   i = i * 2
end

# times と while の違い�C
i = 1
count = 0
while count != 10 do
   if i % 2 == 0 then
	print( i , "\n" )
        count += 1
   end
   i += 1
end

# times と while の違い�D
count = 0
while count != 10 do
   x = rand( 100 )
   if x % 2 == 0 then
	print( x , "\n" )
        count += 1
   end
end

# times と while の違い�E
s = 0.0
n = 0
while s<10.0 do
  r = rand()
  s  += r
  n  += 1
end
puts( "#{n} 回目で10を越えた" )

# 擬似乱数の復習
s = 0.0
s2= 0.0
n =10
n.times{ |i|
  r = rand()
  s  += r
  s2 += r*r
  puts( "#{r} は #{i} 番目の乱数です." )
}
a  = s/n
v  = (s2 - a*a*n)/(n-1)
sd = Math.sqrt( v )
puts( "平均= #{a}, 分散= #{v}, 標準偏差= #{sd}" )

# break文�A
i = 0
total = 0
while i < 10 do
	total += i
   	i += 1
	break if total > 10
end
print( i , " " , total )

# break文�B
i=0
while true do
	puts( i )
	i=i+1
	break if i > 10
end

# 無限ループ
while true do
	puts( "こんにちは" )
end

# break文�C
i = 1000
while true do
   puts( i )
   i = i / 2
   break if i <= 0
end

# break文�D
10.times{ |i|
	puts( i )
	break if i > 5
}

(10..100).each{ |i|
	puts( i )
	break if i > 20
}

# next�@
(0..5).each { |i|
  if ( i==1 || i==4 ) then 
		next 
	end
  puts( "iは #{i}" )
}

# next�A
i=0
while i < 10 do
	i += 1
	if i == 5  then
		next
	end
	puts( i )
end

# next�B
i=0
while i < 10 do
	i += 1
	if i % 2 == 0 then
		next
	end
	puts( i )
end

# 繰り返しのまとめ�A
10.times{ |i|
   print( i , "\n" )
}

(0..9).each{ |i| 
   print( i , "\n" )
}

i = 0
loop{
   break if i == 10
   print( i , "\n" )
   i += 1
}

i = 0
while i < 10 do
   print( i , "\n" )
   i += 1
end

# 繰り返しのまとめ�B
i = 1
loop{
	i = i*2
	break if i > 100
	print( i , "\n" )	
}

i = 2
while i < 100 do	
	print( i , "\n" )
	i = i*2
end

i = 1
while true do	
	i = i*2
	break if i > 100
	print( i , "\n" )
end


# downto
10.downto(0){ |x|
	printf( "x=%2d x^2=%3d\n" , x , x**2 )
}

0.downto(-10){ |x|
	printf( "x=%3d x^2=%6d\n" , x , x**2 )
}

# upto
0.upto(10){ |x|
	print( "x= " , x , "\n" )
}

# step
0.step(10,2){ |x|
	print( x , "\n" )
}

1.step(10,2){ |x|
	print( x , "\n" )
}

10.step(0,-2){ |x|
	print( x , "\n" )
}

9.step(1,-2){ |x|
	print( x , "\n" )
}

# forループ
for x in 1..10 do
	puts( 2**x )
end

for x in -10..10 do
	puts( 2**x )
end

total = 0
for x in 1..10 do
	total += x
end
print( total )