ANARC09A - Seinfeld
I’m out of stories. For years I’ve been writing stories, some rather silly, just to make simple problems look difficult and complex problems look easy. But, alas, not for this one.
You’re given a non empty string made in its entirety from opening and closing braces. Your task is to find the minimum number of “operations” needed to make the string stable. The definition for being stable is as follows:
- An empty string is stable.
- If S is stable, then {S} is also stable.
- If S and T are both stable, then ST (the concatenation of the two) is also stable.
All of these strings are stable: {}, {}{}, and {{}{}}; But none of these: }{, {{}{, nor {}{.
The only operation allowed on the string is to replace an opening brace with a closing brace, or vice-versa.
Input
Your program will be tested on one or more data sets. Each data set is described on a single line. The line is a non-empty string of opening and closing braces and nothing else. No string has more than 2000 braces. All sequences are of even length.
The last line of the input is made of one or more ’-’ (minus signs.)
Output
For each test case, print the following line:
k. N
Where k is the test case number (starting at one,) and N is the minimum number of operations needed to convert the given string into a balanced one.
Example
Input: }{
{}{}{}
{{{}
---
Output: 1. 2
2. 0
3. 1
hide comments
hrishabh:
2015-06-13 22:28:22
easiest one AC in First go :) |
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blumonkey:
2015-05-28 19:10:21
What is the significance of '\r' in python. I got AC in cpp but the same algo gave wa in python. Why? |
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KUMAR ABHISHEK:
2015-05-21 11:21:15
The string to be checked should always be even ? |
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SangKuan:
2015-05-19 14:09:36
notice there is a '\r' at the end of every line,it cost me one time |
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:.Mohib.::
2015-05-19 04:38:45
O(n) simple :) Last edit: 2015-05-19 04:39:08 |
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who cares:
2015-05-04 05:41:05
and the happiest moment when your solution got accepted in first attempt with o(n) ;) |
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Aadil Ahmad:
2015-04-07 19:06:01
My 50th :) :) :) |
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Ayman Mostafa:
2015-03-25 13:06:59
{}{{{}}} is this stable? |
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xxbloodysantaxx:
2015-03-22 11:24:53
That was a total fluke.. I did it by stacks not even thinking what I did (going by intuitions) it went AC .. Now I need to prove the correctness of my algorithm |
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Daniel Carvalho:
2015-03-03 20:08:33
@Mahesh Kohli, yes, it is.
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Added by: | Mohammad Kotb |
Date: | 2009-11-28 |
Time limit: | 3.236s |
Source limit: | 50000B |
Memory limit: | 1536MB |
Cluster: | Cube (Intel G860) |
Languages: | All except: ASM64 BASH JS-RHINO |
Resource: | http://www.icpc-anarc.org |