sgu 183 分类： sgu 2015-03-08 11:09 41人阅读 评论(0) 收藏

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动态规划

开始不会做，
看了Owaski的题解才会的

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#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<ctime>
#include<iostream>
#include<algorithm>

#define INF (1<<30)-1

const int MAXN = 10005, MAXM = 105;
int c[MAXN] = {0} , n , m;
//f(i,j) = min{f(k,i)} + c(j)  //j-i < m  i-k < m
int f[MAXM][MAXM] = {0};

#define mod(a) (a%MAXM)

int main()
{
    int ans = INF;

#ifndef ONLINE_JUDGE
    freopen("sgu183.in","r",stdin);
    freopen("sgu183.out","w",stdout);
#endif  

     scanf("%d%d",&n,&m);

     for(int i = 1; i <= n; i++)
     {
       scanf("%d",&c[i]);
       f[0][i] = c[i];
     }


     for(int i = 1; i < n; i ++)
       for(int j = std::min(i + m -1, n); j > i; j --)
       {
         f[mod(i)][mod(j)] = INF;

         for(int k = std::max(j - m,0); k < i ; k ++)
         {
            f[mod(i)][mod(j)] = std::min(f[mod(i)][mod(j)],f[mod(k)][mod(i)] + c[j]);
         }
       }


      for(int i = std::max(0 ,n - m + 1); i < n; i ++)
        for(int j = i + 1 ; j <= n ; j++) 
         {
            ans = std::min(ans ,f[mod(i)][mod(j)]);
         }

     printf("%d",ans);    

#ifndef ONLINE_JUDGE    
    fclose(stdin);
    fclose(stdout);
#endif  
}