Codeforces Round #139 (Div. 2)C Barcode DP

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#include<iostream>
#include<cstdio>
#include<cstring>
using namespace std ;
const int maxn = 1010;
const int inf = 0x3f3f3f3f ;
int dp[maxn][2] ;
char str[maxn][maxn] ;
int num[maxn];
int sum_b[maxn];
int sum_w[maxn];
int main()
{
   // freopen("in.txt","r",stdin);
    int r , c , x , y;
    //while(~scanf("%d%d%d%d" ,&r , &c ,&x ,&y))
   // {
       scanf("%d%d%d%d" ,&r , &c ,&x ,&y);
        for(int i = 1;i <= r ;i++)
        scanf("%s" ,&str[i][1]) ;
        memset(num , 0 , sizeof(num)) ;
        memset(sum_b , 0 ,sizeof(sum_b)) ;
        memset(sum_w , 0 ,sizeof(sum_w));
        for(int j = 1;j <= c ;j++)
        {
            for(int i = 1;i <= r;i++)
           if(str[i][j] == ‘.‘)
           num[j]++;
        }
        for(int j = 1; j <= c;j++)
        {
           sum_b[j]=(sum_b[j-1]+num[j]) ;
           sum_w[j] = (sum_w[j-1]+ r-num[j]);
        }
        //for(int i = 1;i <= c;i++)
        //printf("%d %d\n",sum_w[i],sum_b[i]) ;
        for(int i = 1;i <= c;i++)
        dp[i][0] = dp[i][1] = inf ;
        dp[0][0] = dp[0][1] =0 ;
        for(int i = 1;i <= c;i++)
        {
            for(int j = x;j <= y && j <= i ;j++)
            dp[i][1] = min(dp[i-j][0]+sum_w[i] -sum_w[i - j] ,dp[i][1]);
            for(int j = x;j <= y && j <= i ;j++)
            dp[i][0] = min(dp[i-j][1] + sum_b[i] - sum_b[i -j],dp[i][0]) ;
        }
        printf("%d\n" ,min(dp[c][0] ,dp[c][1])) ;
    //}
}

Codeforces Round #139 (Div. 2)C Barcode DP

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原文地址：http://blog.csdn.net/cq_pf/article/details/45082029