IOIPALIN - Palindrome 2000
A palindrome is a symmetrical string, that is, a string read identically from left to right as well as from right to left. You are to write a program which, given a string, determines the minimal number of characters to be inserted into the string in order to obtain a palindrome. As an example, by inserting 2 characters, the string "Ab3bd" can be transformed into a palindrome ("dAb3bAd" or "Adb3bdA"). However, inserting fewer than 2 characters does not produce a palindrome.
Input
The first line contains one integer: the length of the input string N, 3 ≤ N ≤ 5000. The second line contains one string with length N. The string is formed from uppercase letters from ‘A’ to ‘Z’, lowercase letters from ‘a’ to ‘z’ and digits from ‘0’ to ‘9’. Uppercase and lowercase letters are to be considered distinct.
Output
The first line contains one integer, which is the desired minimal number.
Example
Input: 5 Ab3bd Output: 2
hide comments
elliot1:
2018-08-25 10:18:59
top down leads to TLE and bottom up works!! this is really weird -_- |
|
one_piece_:
2018-07-10 05:22:27
@boris_dishov
|
|
tanmayak99:
2018-06-03 11:08:43
Similar to Aibohphobia problem
|
|
boris_dishov:
2018-05-23 01:24:37
Hello, I see in the comments (and in the description as well) the LCS. I solved this with something I don't concider LCS (and it was bottom - up), and I am interested to know how it works with LCS if someone can tell me :) |
|
flyingduchman_:
2018-04-03 18:11:32
No Country For Java Man. Only 6 Java Soln passed :-D |
|
pratyush_lzy:
2018-01-25 18:37:23
I don't know why using macros gives TLE :( Removed macros got AC :) |
|
rohit9934:
2017-11-05 13:18:07
|
|
shikhars387:
2017-10-11 19:09:24
Easy DP :)
|
|
raghav_chawla7:
2017-09-26 11:51:39
O(N*N) time and O(N*N) space accepted in 1 go |
|
nikmul19:
2017-09-24 06:56:10
O(n^2) time complexity not passing |
Added by: | Gareev |
Date: | 2010-08-16 |
Time limit: | 1s |
Source limit: | 50000B |
Memory limit: | 1536MB |
Cluster: | Cube (Intel G860) |
Languages: | All except: NODEJS OBJC PERL6 VB.NET |
Resource: | IOI 2000, Day 1 |