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
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amit_taps1997:
2016-10-28 15:53:05
Top Down Memoization AC |
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siddharth_0196:
2016-10-05 11:00:39
String : TLE
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Min_25:
2016-08-05 02:10:30
Almost the same problem as AIBOHP. |
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shayan718:
2016-07-31 19:50:40
top 10 dp problems ;) |
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mkfeuhrer:
2016-07-22 07:35:59
space optimization-> O(3*n)->AC & top down lcs !! |
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SUBHAM SANGHAI:
2016-07-13 16:15:52
use scanf,printf instead of cin,cout and ios base Last edit: 2016-07-13 16:16:08 |
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dwij28:
2016-04-25 10:31:39
Finally did it in O(2 * n) space. Key is that we while building dp matrix in lcs problem, we only need the current and previous rows .. :) |
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maxeinstle:
2016-02-10 17:16:11
Do space optimization in c++ if getting TLE |
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Rishi Vikram:
2016-01-31 22:45:58
O(3*n) memory acceptable. |
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minhthai:
2016-01-18 05:02:52
even O(n) space in java cannot pass :( |
| 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 |
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