编程基础练习作业

01-hello.rb

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

02-variable.rb

@@ -2,12 +2,13 @@
 
 a = 1
 b = 2
-
+temp = a
+a = b
+b = temp
 puts "a 是 #{a}"
 puts "b 是 #{b}"
 
 # ...
 
 puts "a 应该是 2，现在是 #{a}"
 puts "b 应该是 1，现在是 #{b}"
-

03-triangle.rb

@@ -2,10 +2,13 @@
 
 print "请输入直角三角形的高，然后按 Enter: "
 a = gets
+c = a.to_i
 
 print "请输入直角三角形的底边，然后按 Enter: "
 b = gets
-
+d = b.to_i
 # .....
 
-puts "直角三角形的面积是: _________"
+area = (c * d)/2
+
+puts "直角三角形的面积是: #{area}\n"

04-pizzas.rb

@@ -2,11 +2,14 @@
 
 print "请输入有多少片比萨饼，然后按 Enter: "
 pizzas = gets
-
+a = pizzas.to_i
 print "请输入有多少人要吃，然后按 Enter: "
 people = gets
-
+b = people.to_i
 # .....
 
-puts "每人可分得几片: _________ 片"
-puts "还剩下几片: _________ 片"
+c = a / b
+d = c.to_i
+e = a - (d * b)
+puts "每人可分得几片: ____#{d}_____ 片"
+puts "还剩下几片: ____#{e}_____ 片"

05-bmi.rb

@@ -6,12 +6,21 @@
 
 print "请输入您的体重(公斤)，然后按 Enter: "
 weight = gets
-
+a = weight.to_i
 print "请输入您的身高(厘米)，然后按 Enter: "
 height = gets
-
+b = height.to_i
 # .....
+bmi = a / (b*b/10000)
+
 
-puts "您的 BMI 是: _________"
+if bmi < 18.5
+  bmi_target = "过轻"
+elsif bmi < 24
+  bmi_target = "正常"
+else
+  bmi_target = "过重"
+end
+puts "您的 BMI 是: ____#{bmi}_____"
 
-puts "您的 BMI 结果是: _________(过轻或正常或过重)"
+puts "您的 BMI 结果是: ____#{bmi_target}_____(过轻或正常或过重)"

06-interger-positive.rb

@@ -3,8 +3,23 @@
 
 print "请输入一个整数，然后按 Enter: "
 x = gets
-
+y = x.to_i
 # ....
 
-puts "这个数是_____ (正数或零或负数)"
-puts "这个数是_____ (偶数或奇数)"
+if y < 0
+  num = "负数"
+elsif y == 0
+  num = "零"
+else
+  num = "正数"
+end
+
+puts "这个数是__#{num}___ (正数或零或负数)"
+
+math = y % 2
+if math == 0
+  anwser = "偶数"
+else
+  anwser = "奇数"
+end
+puts "这个数是__#{anwser}___ (偶数或奇数)"

07-abcde.rb

@@ -18,5 +18,20 @@
 z = gets
 
 # ....
+x = x.to_i
+y = y.to_i
+z = z.to_i
 
-puts "结果是________(A或B或C或D或E)"
+if x < 0
+  print result = "A"
+elsif (x > 0) && (y > 0) && (z > 0)
+  print result = "B"
+elsif (x > 0) && (y > 0) && (z < 0)
+  print result = "C"
+elsif (x > 0) && (y < 0) && (z > 0)
+  print result = "D"
+elsif (x > 0) && (y < 0) && (z < 0)
+  print result = "E"
+end
+
+puts  "是结果！"

08-find-max.rb

@@ -6,9 +6,10 @@
 print "请输入一个数字y，然后按 Enter: "
 y = gets
 
-print "请输入一个数字z，然后按 Enter: "
+print "请输入一个数nn 字z，然后按 Enter: "
 z = gets
 
 # ....
 
-puts "最大的数是 ________(x或y或z)"
+result = [x, y, z].max
+puts "最大的数是 #{result}"

09-function.rb

@@ -1,7 +1,9 @@
 # 题目: 输入直角三角形的宽和高，输出三角形的面积
 
 def calculate_area(a, b)
-  # ....
+  a = a.to_f
+  b = b.to_f
+  calculate_area = a * b * 0.5
 end
 
 print "请输入直角三角形的高，然后按 Enter: "
@@ -12,4 +14,4 @@ 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 +1,10 @@
 # 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
+  find_max = [x, y, z].max
 end
 
 print "请输入一个数字x，然后按 Enter: "
@@ -16,4 +20,4 @@ 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

@@ -1,9 +1,12 @@
 # 题目: 列出 1 到 100 之间，所有 7 的倍数
 
 i = 1
-while ( i <= 100 )
 
-  # ....
+while ( i <= 100  )
 
   i+=1
-end
+  if i % 7 == 0
+    puts i
+  end
+
+end

12-sum-even.rb

@@ -4,10 +4,12 @@
 total = 0
 
 while ( i <= 100 )
-
+  if i % 2 == 0
+    total = total + i
+  end
   # ....
 
   i+=1
 end
 
-puts total
+puts total

13-nn.rb

@@ -8,4 +8,15 @@
 #
 #   end
 # end
-
+i = 0
+j = 0
+n = n.to_i
+while (i <= n )
+  while (j <= n)
+    result = i * j
+    puts "#{i} x #{j} = #{result}"
+    j+=1
+  end
+  i+=1
+  j = 0
+end

14-prime.rb

@@ -1,7 +1,19 @@
 # 输入一个数字 N，请检查是不是质数
 
 def is_prime(n)
-# ....
+  i = 2
+  while (i <= n/2)
+    a = n % i
+    if a != 0
+      i+=1
+    else
+      break
+      return false
+    end
+  end
+  if i > n / 2
+    return true
+  end
 end
 
 print "请输入数字 N，然后按 Enter: "

15-guess-number.rb

@@ -5,13 +5,16 @@
 while (true)
   print "请猜一个 0~99 的数字 N，然后按 Enter: "
   n = gets
+  if n.to_i < target
+    puts "太低了，再猜一次"
+  elsif n.to_i > target
+    puts "太高了，再猜一次"
+  end
 
-  #puts "太低了，再猜一次"
-  #puts "太高了，再猜一次"
 
   if n.to_i == target
     puts "恭喜猜中啦! "
     break
   end
 
-end
+end

16-array-sum.rb

@@ -1,11 +1,10 @@
 # 给定一阵列内含数字，输出最大值
 
 def find_max(array)
-  #....
+  find_max = array.max
 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

@@ -11,10 +11,13 @@
     arr << user_input.to_i
   end
 end
+sum = 0
+arr.each { |i| sum += i }
+average = sum/arr.length
 
 puts arr.to_s
 
-puts "总和是 _____"
-puts "平均是 _____"
-puts "最大值是 _____"
-puts "最小值是 _____"
+puts "总和是 __#{sum}___"
+puts "平均是 __#{average}___"
+puts "最大值是 __#{arr.max}___"
+puts "最小值是 __#{arr.min}___"

18-square.rb

@@ -3,8 +3,10 @@
 arr = []
 
 print "请输入数字 N，然后按 Enter: "
-n = gets
+n = gets.to_i
 
 # ...
-
-puts arr.to_s
+(0..n).each_with_index do |i, j|
+  arr << j ** 2
+end
+puts arr.to_s

19-filter.rb

@@ -1,9 +1,17 @@
 # 给定一阵列内含数字，输出另一个数组只包含偶数
 
 def filter_even(arr)
-  #...
+  new_arr = []
+
+  arr.each do |i|
+    if i % 2 == 0
+      new_arr << i
+    end
+  end
+  print "#{new_arr}"
+
 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

@@ -2,10 +2,19 @@
 # Hint: 可用 arr.sort 排序，和 arr.uniq 去除重复
 
 def filter_even(arr)
-  #...
+  new_arr = []
+
+  arr.each do |i|
+    if i % 2 == 0
+      new_arr << i
+    end
+  end
+
+  print "#{new_arr.sort.uniq}"
+
 end
 
 arr =  [7, 68, 42, 46, 9, 91, 77, 46, 86, 1]
 
 
-puts "________" # 应该是 [42, 46, 68, 86]
+puts "___#{filter_even(arr)}_____" # 应该是 [42, 46, 68, 86]

21-selection-sort.rb

@@ -2,11 +2,16 @@
 # https://zh.wikipedia.org/wiki/选择排序
 
 def insertion_sort(arr)
-  #...
+  (0...arr.length).each do |i|
+     min, index = arr[i], i
+     (i...arr.length).each { |j| min, index = arr[j], j if arr[j] < min }
+     arr[i], arr[index] = arr[index], arr[i]
+   end
+   arr
 end
 
 arr =  [7, 68, 42, 46, 9, 91, 77, 46, 86, 1]
 
 answer = insertion_sort(arr)
 
-puts answer.to_s # 应该是 [1, 7, 9, 42, 46, 46, 68, 77, 86, 91]
+puts answer.to_s # 应该是 [1, 7, 9, 42, 46, 46, 68, 77, 86, 91]