HDU 1024 Max Sum Plus Plus

题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=1024

分析：dp，对于第i个数有两种情况，一个是在前一个数所在的组；一个是单独开一组，那么前一个数就不一定需要，此时要找1~(i -1)中最大

#include<iostream>
#include<sstream>
#include<cstdio>
#include<cstdlib>
#include<string>
#include<cstring>
#include<algorithm>
#include<functional>
#include<iomanip>
#include<numeric>
#include<cmath>
#include<queue>
#include<vector>
#include<set>
#include<cctype>
#define PI acos(-1.0)
const int INF = 0x3f3f3f3f;
const int NINF = -INF - 1;
const int maxn = 1e6 + 5;
typedef long long ll;
using namespace std;
int m, n;
int arr[maxn], dp[maxn], Max[maxn];
int main()
{
    while (scanf("%d%d", &m, &n) != EOF)
    {
        int mmax;
        for (int i = 1; i <= n; ++i)
            scanf("%d", &arr[i]);
        memset(dp, 0, sizeof(dp));
        memset(Max, 0, sizeof(Max));
        for (int i = 1; i <= m; ++i)
        {
            mmax = -INF;
            for (int j = i; j <= n; ++j)
            {
                dp[j] = max(dp[j - 1] + arr[j], Max[j - 1] + arr[j]);
                Max[j - 1] = mmax;
                mmax = max(mmax, dp[j]);
            }
        }
        printf("%d
", mmax);
    }
    return 0;
}