is O(n) solution possible

________________________________
From: abhijith reddy <[email protected]>
To: [email protected]
Sent: Friday, 6 May 2011 9:47 PM
Subject: Re: [algogeeks]


dp1[i][j] will hold 1/0 depending upon whether string str[i...j] is a 
palindrome or not.
Now let dp2[i][j] be the minimum number of cuts required to split it into 
palindromes.
if str[i...j] is a palindrome then '0' cuts are required.
To get the number of cuts required for str[i...j] we try all possible positions 
between i & j and take minimum of all.


On Fri, May 6, 2011 at 8:23 PM, sourabh jakhar <[email protected]> wrote:

can you explain the logic
>
>
>
>On Fri, May 6, 2011 at 8:02 PM, abhijith reddy <[email protected]> 
>wrote:
>
>O(N^3) DP
>>-------------------------------------------------------------------------------------------------------------
>>char str[MAX];
>>int dp1[MAX][MAX],dp2[MAX][MAX];
>>
>>int isPalin(int low,int high)
>>{
>>    if(low>=high) return 1;
>>    if(dp1[low][high]!=-1) return dp1[low][high];
>>    return dp1[low][high]=(str[low]==str[high])?isPalin(low+1,high-1):0;
>>}
>>
>>int minCuts(int low,int high)
>>{
>>    if(isPalin(low,high)) return 0;
>>    if(dp2[low][high]!=-1) return dp2[low][high];
>>    int ans=1e9;
>>    for(int i=low;i<high;i++)
>>        ans=min(ans,1+minCuts(low,i)+minCuts(i+1,high));
>>    return dp2[low][high]=ans;
>>}
>>
>>-------------------------------------------------------------------------------------------------------------
>>
>>
>>
>>On Fri, May 6, 2011 at 4:23 PM, sourabh jakhar <[email protected]> 
>>wrote:
>>
>>You are given a large string. You need to cut the string into chunks such 
>>that each 
substring that you get is a palindrome. Remember that each 1 length 
string is always a palindrome. You need to find the minimum number of 
cuts that you need to make such that each substring is a palindrome. 
>>>
>>>-- 
>>>SOURABH JAKHAR,(CSE)(3 year)
>>>ROOM NO 167 ,
>>>TILAK,HOSTEL
>>>'MNNIT ALLAHABAD
>>>
>>>
>>>The Law of Win says, "Let's not do it your way or my way; let's do it the 
>>>best way."
>>>
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>
>
>-- 
>SOURABH JAKHAR,(CSE)(3 year)
>ROOM NO 167 ,
>TILAK,HOSTEL
>'MNNIT ALLAHABAD
>
>
>The Law of Win says, "Let's not do it your way or my way; let's do it the best 
>way."
>
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>You received this message because you are subscribed to the Google Groups 
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>

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