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DP就是动态规划

Posted by number at 2006-07-27 04:26:13 on Problem 2817
In Reply To:小声的问一句,状态空间DP是什么 Posted by:yiyiyi4321 at 2006-07-27 02:27:22
放好前i个词后,前i个词对后面的词的影响只与第i个词前的空格数有关
也就是满足无后效性
那么用f[i][j]表示放好前i个词,且第i个词前有j个空格的最小代价
那么可以有这样的推导:

f[i+1][j] = 
Min{f[i][k] + (第i个词前有k个空格,与第i+1个词前有j个空格所产生的代价)}
(其中k 取遍 1..n-strlen(word[i]))
这样算出所有的f[i][j]
那么:
ans = Min{f[n][i]}(i取遍1..n-strlen(n))
就是我们要找的答案
> 用某i个,第j个在最后的数作状态  这句话什么意思??

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