# 配列の要素への代入
name = [ "A" , "B" , "C" , "D" , "E" ]
test = [ 85 , 60 , 5, 100 , 50 ]

name[ 3 ] = "d"
test[ 3 ] = 90

p name
p test

# 最後の要素への追加
name = [ "A" , "B" , "C" , "D" , "E" ]
test = [ 85 , 60 , 5, 100 , 50 ]

name[ name.length ] = "F"
test[ test.length ] = 70

p name
p test

# 平均点を求める�@
name = [ "A" , "B" , "C" , "D" , "E" ]
test = [ 85 , 60 , 5, 100 , 50 ]

sum = 0
test.length.times{ |i|
	sum += test[ i ]
}
print( "平均点 --> " , sum / test.length )

# 平均点を求める�A
name = [ "A" , "B" , "C" , "D" , "E" ]
test = [ 85 , 60 , 5, 100 , 50 ]

sum = 0
(0..test.length-1).each{ |i|
	sum += test[ i ]
}
print( "平均点 --> " , sum / test.length )

# 平均点を求める�B
name = [ "A" , "B" , "C" , "D" , "E" ]
test = [ 85 , 60 , 5, 100 , 50 ]

sum = 0
test.each{ |i|
	sum += i
}
print( "平均点 --> " , sum / test.length )

# 平均点未満の名前を出力
name = [ "A" , "B" , "C" , "D" , "E" ]
test = [ 85 , 60 , 5, 100 , 50 ]
sum = 0
test.each{ |i|
	sum += i
}
average = sum / test.length

print( "平均点未満は...\n" )
test.length.times{ |i|
	if average > test[ i ] then
		print( name[ i ] , ": " , test[ i ] , "点\n" )
	end
}

# 最高点とその名前を出力
name = [ "A" , "B" , "C" , "D" , "E" ]
test = [ 85 , 60 , 5, 100 , 50 ]

max = 0
test.length.times{ |i|
	if test[ max ] < test[ i ] then
		max = i
	end
}
print( "最高点は" , name[ max ] , " の " , test[ max ] , "点です\n" )

# 最低点とその名前を出力
name = [ "A" , "B" , "C" , "D" , "E" ]
test = [ 85 , 60 , 5, 100 , 50 ]

min = 0
test.length.times{ |i|
	if test[ min ] > test[ i ] then
		min = i
	end
}
print( "最低点は" , name[ min ] , " の " , test[ min ] , "点です\n" )

# 検索�@
name = [ "A" , "B" , "C" , "D" , "E" ]
test = [ 85 , 60 , 5, 100 , 50 ]

search = "B"
name.length.times{ |i|
	if name[ i ] == search then
		print( search , " の点は " , test[ i ] , "点です\n" )
		break
	end
}

# 検索�A
name = [ "A" , "B" , "C" , "D" , "E" ]
test = [ 85 , 60 , 5, 100 , 50 ]

line = ARGV[ 0 ]
search = line.chomp

name.length.times{ |i|
	if name[ i ] == search then
		print( search , " の点は " , test[ i ] , "点です\n" )
		break
	end
}

# 二重ループ
(0..9).each{ |x|
	(0..9).each{ |y|
		z = x*x + y*y
		print( " x = " , x , " y = " , y , ": z= " , z , "\n" )
	}
}

# 二重ループの例�@
(1..9).each{ |x|
	(1..9).each{ |y|
		printf( " %d×%d=%2d" , x , y , x * y  ) 
	}
	print( "\n" )
}

# 二重ループの例�A
(1..9).each{ |x|
	(1..9).each{ |y|
		if x == y then
			print( "1 " )
		else
			print( "0 " )
		end	
	}
	print( "\n" )
}

# 二重ループの例�B
(1..9).each{ |x|
	(1..9).each{ |y|
		if x == (10-y) then
			print( "1 " )
		else
			print( "0 " )
		end	
	}
	print( "\n" )
}

# 二重ループの例�C
(1..9).each { |i|
  (1..i).each { |j| 
		print( j ) 
　}
　print ( "\n" )
}

# 二重ループの例�D
(1..9).each { |i|
  (1..(10-i)).each{ |j| 
	  print( j ) 
  }
  print ( "\n" )
}

# 二重ループの例�E
11.times { |i|
  d = Math.sqrt( 100 - i*i ).to_i
  (1..d).each{ 
	print( " " )
  }
  ((d+1)..10).each{
	 print( "*" )
  } 
  print( "\n" )
}

# 二重ループの例�F
11.times { |i|
  d = Math.sqrt( 400 - 4*i*i ).to_i
  (1..d).each{ 
	print( " " )
  }
  ((d+1)..20).each{ 
	print( "*" )
  } 
  print( "\n" )
}

# 金利の計算�@
r = 0.05
n = 10
m = 10000
(1..n).each{ |i|
	x = 10000.0 * ( 1.0 + r ) ** i.to_f
	printf( "%2d 年後は %d\n" , i , x.to_i )
}	

# 金利の計算�A
n = 10
m = 10000

(1..n).each{ |i|
	printf( "%2d 年後は " , i )
	(1..10).each{ |j|
		r = j * 0.05
		x = 10000.0 * ( 1.0 + r ) ** i.to_f
		printf( "%6d " , x.to_i )
	}
	print( "\n" )
}	

# エラトステネスの篩: プログラム例�@
sieve = Array.new(101)
sieve.length.times { |i|
   sieve[i] = 1
}

sieve[0]=0
sieve[1]=0
(2..sieve.length-1).each { |i|
  (i*2).step(sieve.length-1, i) { |j| 
	sieve[j]=0 
   }
}

sieve.length.times { |i| 
	print( "#{i} " ) if sieve[i] != 0
}

# エラトステネスの篩: プログラム例�A
sieve = Array.new(101)
sieve.length.times { |i| 
  sieve[i] = i # ちょっと工夫
}
sieve[0]=0
sieve[1]=0
(2..sieve.length-1).each { |i|
  (i*2).step(sieve.length-1, i) { |j| 
	sieve[j]=0 
  }
}
sieve.each { |p| 
	print( "#{p} " ) if p!=0 
}

# 配列の初期化�@
sieve = Array.new(10).fill{ 1 }

# 配列の初期化�A
sieve = Array.new(10).fill{ |i| i }

# bubble sort のプログラム�@
a=[ 4,1,8,2,6,5 ]
p a
(0..a.length-1).each{ |i| 
  (a.length-2).downto(i) { |j|
    if a[j]>a[j+1] then
      w = a[j]
	   a[j]=a[j+1]
      a[j+1]=w
    end
  }
}
p a

# bubble sort のプログラム�A
a=[ 4,1,8,2,6,5 ]
p a
(0..a.length-1).each{ |i| 
  (a.length-2).downto(i) { |j|
    if a[j]<a[j+1] then
      w = a[j]
      a[j]=a[j+1]
      a[j+1]=w
    end
  }
}
p a

# bubble sort のプログラム�B
a=Array.new(10)
a.length.times{ |i|
    a[ i ] = rand( 10 )
}
p a
(0..a.length-1).each{ |i| 
  (a.length-2).downto(i) { |j|
    if a[j]>a[j+1] then
      w = a[j]
      a[j]=a[j+1]
      a[j+1]=w
    end
  }
}
p a