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dynamic beginner
By vsanjay_nitdgp, history, 11 years ago, In English

sir..i am dp beginner....i solved the following problem with brute-force.....but i want to know approach for DP solutions.....

pls explain the approach clearly...

thanks in advance

http://codeforces.me/problemset/problem/189/A

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11 years ago, hide # |
 
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Ok, lets calc value dp[i] — maximum number of peaces we can cut rope with length i.

How to calc it?

Let's look to last peace. It can have length a, b or c. If we know length of last peace we can reduse problem to probl with smaller i.

For example, it length of last peace is a answer equal to dp[i-a]+1.

But we can choose any of three types of peaces so we need to take best.

And we get a formula:

dp[i]=max(dp[i-a],dp[i-b],dp[i-c])+1

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