字符串格式算法建议

你没说什么语言所以。。。爪哇!

public void foo(String input, String q) {
  //First clean up the input string so that all tokens are delimited by one space
  input = input.replaceAll(" *", " ");

  String[] inputTokens = input.split(",");       
  String[] queries = q.split(",");
  for (String query : queries) {
    if (query.endsWith(-)) {
      query = query.replace("-", "");
      for (int i = Integer.parseInt(query), i <= inputTokens.length; i++) {
        System.out.println(inputTokens[i]);
      }
    } else {
      System.out.println(inputTokens[Integer.parseInt(query)]);
    }
  }

使用只匹配单个空格的正则表达式(例如 "[^ ] [^ ]"

这里有一个用Python实现的方法

import re

def f(s1,s2):
    items = re.findall("[^ ]+| +",s1)
    result = []
    for idx in s2.split(','):
        i,j,_ = idx.partition("-")
        i=int(i)-1
        result.append(''.join(items[i:None if j else i+1]))
    return ','.join(result)

assert f("A B C  D  E", "3-") == "C  D  E"
assert f("A B C  D  E", "1,2") == "A,B"
assert f("A B C  D  E", "4-,1,2") == "D  E,A,B"