poj 1976 A Mini Locomotive

#include<cstdio>#include<cstring>#include<algorithm>using namespace std;int dp[50005][4],sum[50005];int main(){    int T;    for(scanf("%d",&T);T;T--)    {        int n,m;        scanf("%d",&n);        memset(dp,0,sizeof(dp));        sum[0]=0;        for(int i=1,tp;i<=n;i++)        { scanf("%d",&tp); sum[i]=sum[i-1]+tp;        }        scanf("%d",&m);        for(int i=1;i<=n;i++)        { for(int j=1;j<=3;j++) {     if(i<=m*j)         dp[i][j]=sum[i];     else         dp[i][j]=max(dp[i-1][j],dp[i-m][j-1]+sum[i]-sum[i-m]); }        }        printf("%dn",dp[n][3]);    }    return 0;}