行内の繰り返しを見つける。
設問
Given a sequence, write a program to detect cycles within it.
Input sample:
A file containing a sequence of numbers (space delimited). The file can have multiple such lines. e.g
2 0 6 3 1 6 3 1 6 3 1
Ensure to account for numbers that have more than one digit eg. 12. If there is no sequence, ignore that line.
Output sample:
Print to stdout the first sequence you find in each line. Ensure that there are no trailing empty spaces on each line you print. e.g.
6 3 1
やってみた
文字列の後ろから繰り返しがないかをチェック。
繰り返し文字列の長さは、2文字以上、全体の半分以下。
#!/usr/bin/env ruby def detect_cycle(stack) (2..stack.size/2).each do |i| assume_cycle = stack[-i, i] next_cycle = stack[-i*2, i] return assume_cycle.join(" ") if assume_cycle == next_cycle end '' end ARGF.lines do |line| puts detect_cycle(line.split(/\s/)) end
あまりきれいじゃないなー。
