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How to solve this question using dp .

By deepak_097, history, 8 years ago, In English

Problem- link

Please anybody explain the soln.

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8 years ago, hide # |
 
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see Ashishgup solution . dp cant be more neat than his solution

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    8 years ago, hide # ^ |
     
    Vote: I like it +1 Vote: I do not like it

    I saw but unable to understand this single line means why everyone is using suffix array even if we are processing from left to right :(

    ans = max(dp(i + 1), a[i] + suf[i + 1] — dp(i + 1));

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      8 years ago, hide # ^ |
       
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      My logic was:

      DP(i) stores the maximum value a particular player can get if he starts at the ith index and goes till the end of the array.

      One possibility is, I retain my turn and skip the element, thus going to dp(i+1).

      Other possibility is, I take the ith element (and get a score of a[i]) and lose my turn. If I lose my turn, then the score I get is:

      sum of remaining elements — the maximum score that the other player can get if he starts at index i + 1.

      That is, suf[i+1] — dp(i+1).

      Hence the line: ans = max(dp(i + 1), a[i] + suf[i + 1] — dp(i + 1)).

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