Question

任何人都可以解释一下这段代码吗？我不明白具体：

  elsif idx2 > idx1
    is_repeat = true
  end

为什么我们要比较指数以确定是否有信件重复？
if语句中的“下一个”术语是做什么的？

完整代码如下所示：

# Write a method that takes in a string and returns the number of
# letters that appear more than once in the string. You may assume
# the string contains only lowercase letters. Count the number of
# letters that repeat, not the number of times they repeat in the
# string.
#
# Difficulty: hard.

def num_repeats(array)
  repeats = 0

  idx1 = 0
  while idx1 < array.length
    is_repeat = false
    idx2 = 0
    while idx2 < array.length
      if array[idx1] != array[idx2]
        idx2 += 1
        next
      elsif idx2 < idx1
        # will have previously counted this repeat
        break
      elsif idx2 > idx1
        is_repeat = true
      end

      idx2 += 1
    end

    if is_repeat
      repeats += 1
    end

    idx1 += 1
  end

  return repeats
end

Answer 1

如果之前的条件（if idx2 < array.length和elsif idx2 < idx1）都是false但idx2 > idx1是true，那么将局部变量is_repeat设置为true ...

请解释这个返回重复字母数的Ruby方法

1 个答案: