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
ajay_5097:
2016-04-14 21:11:06
one silly mistake !!
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vsp4:
2016-03-29 07:16:45
Using getline(cin, str) gives WA. But with scanf it gets AC. Huh? |
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nonushikhar:
2016-03-01 19:23:57
stack o(n) |
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insomniac:
2016-02-17 23:09:38
no dp! no stack! O(n) time O(1) space :) |
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parkjinsang:
2016-02-11 14:47:14
How to solve this problem using dp? anyone? |
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PRANJIT BHARALI:
2016-02-04 20:11:01
lol.. !!! |
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try2catch:
2016-01-23 10:35:01
single shot AC problem....... B)
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dwij28:
2016-01-13 06:12:51
150th AC.. Horrible input format.. I got an AC without stack, but my stack solution failed for some unknown reasons.. Also, people who used DP to solve this are trying to cut nails with a sword. DP is so powerful, why waste it on adhoc stuff ? |
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Akshay Damle:
2015-10-16 18:04:15
Input format weird. Python: WA, C++: AC. Same logic. |
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Shubham Garg:
2015-09-28 13:03:54
There is definitely some problems in the input when used getchar () for taking input it costed me 4 wrong answers but using scanf got accepted. |
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 |