编程基础练习簿

01-hello.rb

@@ -5,4 +5,4 @@
 
 # ...
 
-puts "(请替换成最后的答案)"
+puts "Hello, #{your_name}"

02-variable.rb

@@ -6,8 +6,9 @@
 puts "a 是 #{a}"
 puts "b 是 #{b}"
 
-# ...
+c = a
+a = b
+b = c
 
 puts "a 应该是 2，现在是 #{a}"
 puts "b 应该是 1，现在是 #{b}"
-

03-triangle.rb

@@ -6,6 +6,8 @@
 print "请输入直角三角形的底边，然后按 Enter: "
 b = gets
 
+
 # .....
+s = (a.to_f*a.to_f)/2
 
-puts "直角三角形的面积是: _________"
+puts "直角三角形的面积是: #{s}"

04-pizzas.rb

@@ -7,6 +7,11 @@
 people = gets
 
 # .....
+ s1 = pizzas
+ s2 = people
+ t1 = s1.to_i/s2.to_i
+ t2 = s1.to_i%s2.to_i
 
-puts "每人可分得几片: _________ 片"
-puts "还剩下几片: _________ 片"
+
+puts "每人可分得几片: #{t1} 片"
+puts "还剩下几片: #{t2} 片"

05-bmi.rb

@@ -11,7 +11,18 @@
 height = gets
 
 # .....
+w = weight
+h = height
+b = w.to_f/(h.to_f*h.to_f)*100*100
 
-puts "您的 BMI 是: _________"
+if b < 18.5
+  t = "过轻"
+elsif b >= 24
+  t = "过重"
+else ( b >= 18.5 ) && ( b < 24 ) 
+  t = "正常"
+end
 
-puts "您的 BMI 结果是: _________(过轻或正常或过重)"
+puts "您的 BMI 是: #{b}"
+
+puts "您的 BMI 结果是: #{t}(过轻或正常或过重)"

06-interger-positive.rb

@@ -5,6 +5,23 @@
 x = gets
 
 # ....
+s = x.to_i
+s1 = s%2
 
-puts "这个数是_____ (正数或零或负数)"
-puts "这个数是_____ (偶数或奇数)"
+if s < 0
+  t = "负数"
+elsif s > 0
+  t = "正数"
+else
+  t = "零"
+end
+
+if s1 > 0
+  t1 = "奇数"
+elsif s1 == 0
+  t1 = "偶数"
+end
+
+
+puts "这个数是: #{t}(正数或零或负数)"
+puts "这个数是: #{t1} (偶数或奇数)"

07-abcde.rb

@@ -18,5 +18,43 @@
 z = gets
 
 # ....
+=begin
+t1 = x.to_i
+t2 = y.to_i
+t3 = z.to_i
 
-puts "结果是________(A或B或C或D或E)"
+if t1 < 0
+  s = "A"
+elsif t1 > 0 && t2 > 0 && t3 > 0
+  s = "B"
+elsif t1 > 0 && t2 > 0 && t3 < 0
+  s = "C"
+elsif t1 > 0 && t2 < 0 && t3 > 0
+  s = "D"
+else t1 >0 && t2 < 0 && t3 < 0
+  s = "E"
+end
+=end
+
+x = x.to_i
+y = y.to_i
+z = z.to_i
+
+if x < 0
+  s = "A"
+elsif x > 0 && y > 0
+  if z > 0
+    s = "B"
+  elsif z < 0
+    s = "C"
+  end
+elsif x > 0 && y < 0
+  if z > 0
+    s = "D"
+  elsif z < 0
+    s = "E"
+  end
+end
+
+
+puts "结果是: #{s} (A或B或C或D或E)"

08-find-max.rb

@@ -10,5 +10,20 @@
 z = gets
 
 # ....
+x = x.to_i
+y = y.to_i
+z = z.to_i
 
-puts "最大的数是 ________(x或y或z)"
+
+
+if x >= y && x >= z
+  t = "x"
+elsif y >= z && y >= x
+  t = "y"
+elsif z >= x && z >= y
+  t = "z"
+end
+
+# t = [x, y, z].max
+
+puts "最大的数是: #{t} (x或y或z)"

09-function.rb

@@ -2,6 +2,9 @@
 
 def calculate_area(a, b)
   # ....
+  a = a.to_f
+  b = b.to_f
+  s = ( a * b ) / 2
 end
 
 print "请输入直角三角形的高，然后按 Enter: "
@@ -12,4 +15,4 @@ def calculate_area(a, b)
 
 answer = calculate_area(a,b)
 
-puts "直角三角形的面积是: #{answer}"
+puts "直角三角形的面积是: #{answer}"

10-function.rb

@@ -1,6 +1,18 @@
 # 题目: 使用者输入 x,y,z，请输出三个数中最大的数
 
 def find_max(x, y, z)
+  x = x.to_f
+  y = y.to_f
+  z = z.to_f
+
+  if x >= y && x >= z
+    t = "x"
+  elsif y >= z && y >= x
+    t = "y"
+  elsif z >= x && z >= y
+    t = "z"
+  end
+
 end
 
 print "请输入一个数字x，然后按 Enter: "
@@ -16,4 +28,4 @@ def find_max(x, y, z)
 
 answer = find_max(x,y,z)
 
-puts "最大的数是 #{answer}"
+puts "最大的数是 #{answer}"

11-seven.rb

@@ -4,6 +4,9 @@
 while ( i <= 100 )
 
   # ....
-
-  i+=1
-end
+  if i % 7 == 0
+    puts i
+  end
+    i += 1
+
+end

12-sum-even.rb

@@ -7,7 +7,12 @@
 
   # ....
 
+  if i % 2 == 0
+    puts i
+    total += i
+  end
+
   i+=1
 end
 
-puts total
+puts total

13-nn.rb

@@ -2,10 +2,21 @@
 
 print "请输入数字 N，然后按 Enter: "
 n = gets
+n = n.to_i
+x = x.to_i
+y = y.to_i
 
 # while ( ... )
 #   while ( ...)
 #
 #   end
 # end
-
+x = 0
+while x <= n
+  y = 0
+  while y <= n
+    puts "#{x} x #{y} = #{x*y}"
+    y += 1
+  end
+  x += 1
+end

14-prime.rb

@@ -2,6 +2,24 @@
 
 def is_prime(n)
 # ....
+  if n < 2
+    return false
+  end
+
+  if n == 2
+    return true
+  end
+
+  if n > 2
+    i = 2
+    while i <= n/2
+      if n % i == 0
+        return false
+      end
+      i += 1
+    end
+    return true
+  end
 end
 
 print "请输入数字 N，然后按 Enter: "

15-guess-number.rb

@@ -12,6 +12,10 @@
   if n.to_i == target
     puts "恭喜猜中啦! "
     break
+  elsif n.to_i > target
+    puts "太高了，再猜一次"
+  elsif n.to_i < target
+    puts "太低了，再猜一次"
   end
 
-end
+end

16-array-sum.rb

@@ -2,10 +2,16 @@
 
 def find_max(array)
   #....
+  m = array[0]
+  array.each do |i|
+    if m < i
+      m = i
+    end
+  end
+  return m
 end
 
 arr = [8, 12, 36, 53, 9, 75, 3, 71, 59, 88]
 
 max = find_max(arr)
 puts "Max is #{max}" # 应该是 88
-

17-array-stats.rb

@@ -14,7 +14,22 @@
 
 puts arr.to_s
 
-puts "总和是 _____"
-puts "平均是 _____"
-puts "最大值是 _____"
-puts "最小值是 _____"
+sum = 0
+m = n = arr[0]
+arr.each do |i|
+  sum += i
+  if m < i
+    m = i
+  end
+  if n > i
+    n = i
+  end
+end
+
+average = sum / arr.size
+
+
+puts "总和是 #{sum}"
+puts "平均是 #{average}"
+puts "最大值是 #{m}"
+puts "最小值是 #{n}"

18-square.rb

@@ -5,6 +5,12 @@
 print "请输入数字 N，然后按 Enter: "
 n = gets
 
+n = n.to_i
+
+(0..n-1).each_with_index do |i|
+  # arr.push (i*i)
+  arr << i ** 2
+end
 # ...
 
-puts arr.to_s
+puts arr.to_s

19-filter.rb

@@ -2,8 +2,15 @@
 
 def filter_even(arr)
   #...
+  arr2 = []
+  arr.each do |i|
+    if i % 2 == 0
+      arr2.push (i)
+    end
+  end
+  arr2
 end
 
 arr =  [7, 68, 42, 46, 9, 91, 77, 46, 86, 1]
 
-puts filter_even(arr).to_s # 应该是 [68, 42, 46, 46, 86]
+puts filter_even(arr).to_s # 应该是 [68, 42, 46, 46, 86]

20-sorting.rb

@@ -3,9 +3,17 @@
 
 def filter_even(arr)
   #...
+  arr2 = []
+  arr.each do |i|
+    if i % 2 == 0
+      arr2.push(i)
+    end
+  end
+  arr2 = arr2.uniq
+  arr2 = arr2.sort
 end
 
 arr =  [7, 68, 42, 46, 9, 91, 77, 46, 86, 1]
 
 
-puts "________" # 应该是 [42, 46, 68, 86]
+puts filter_even(arr).to_s # 应该是 [42, 46, 68, 86]