вторник, 14 января 2014 г.

Codility. Train. Brackets ★

A string S consisting of N characters is considered to be properly nested if any of the following conditions is true:
  • S is empty;
  • S has the form "(U)" or "[U]" or "{U}" where U is a properly nested string;
  • S has the form "VW" where V and W are properly nested strings.
For example, the string "{[()()]}" is properly nested but "([)()]" is not.
Write a function:
int solution(char *S);
that, given a string S consisting of N characters, returns 1 if S is properly nested and 0 otherwise.
For example, given S = "{[()()]}", the function should return 1 and given S = "([)()]", the function should return 0, as explained above.
Assume that:
  • N is an integer within the range [0..200,000];
  • string S consists only of the following characters: "(", "{", "[", "]", "}" and/or ")".
Complexity:
  • expected worst-case time complexity is O(N);
  • expected worst-case space complexity is O(N) (not counting the storage required for input arguments).


Solution:
from string import maketrans

def solution(S):
  b, t = [], maketrans('}])','{[(')
  for i in S:
    if i in '{[(':
      b.append(i); continue
    if len(b) == 0 or \
      i.translate(t) != b.pop():
      return 0
  return 1 if len(b) == 0 else 0

1 комментарий:

  1. Здравствуйте. У меня есть задачки кодилити которых нет в этом блоге и которые было бы интересно осветить. Если интересно дайте знать вышлю вам мое мыло menvil.menvil@gmail.com

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