XJOI3354题解

#include <cstdio>
#include <queue>
#include <cstring>
#define ll long long
using namespace std;
ll p[5005],f[5005],Max[2][5005];
int main()
{
    int n, m, k, i;
    scanf("%d %d %d",&n,&m,&k);
    for (i=1;i<=n;i++)scanf("%lld",&p[i]);
    ll max_ans=0;
    for (i=1;i<=k;i++){
        int j;Max[0][0] = 0;
        for (j=(i-1)*m+1;j<=(n-m+1);j++){
            ll tmp = 0;
            for (int K=0;K<m;K++)tmp+=p[j+K];
            if (j - m > 0)f[j]=Max[0][j - m]+tmp;else f[j]=tmp;
            if (f[j]>Max[1][j-1]||j==((i-1)*m+1))Max[1][j]=f[j]; else Max[1][j]=Max[1][j-1];
            if (i==k&&f[j]>max_ans)max_ans=f[j];
        }
        memset(Max[0],0,sizeof(Max[0]));
        for (j=(i-1)*m+1;j<=(n-m+1);j++)Max[0][j]=Max[1][j];
    }
    printf("%lld",max_ans);
    return 0; 
}