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

 1 #include<iostream>
 2 #include<sstream>
 3 #include<cstdio>
 4 #include<cstdlib>
 5 #include<string>
 6 #include<cstring>
 7 #include<algorithm>
 8 #include<functional>
 9 #include<iomanip>
10 #include<numeric>
11 #include<cmath>
12 #include<queue>
13 #include<vector>
14 #include<set>
15 #include<cctype>
16 #define PI acos(-1.0)
17 const int INF = 0x3f3f3f3f;
18 const int NINF = -INF - 1;
19 const int maxn = 1e6 + 5;
20 typedef long long ll;
21 using namespace std;
22 int m, n;
23 int arr[maxn], dp[maxn], Max[maxn];
24 int main()
25 {
26     while (scanf("%d%d", &m, &n) != EOF)
27     {
28         int mmax;
29         for (int i = 1; i <= n; ++i)
30             scanf("%d", &arr[i]);
31         memset(dp, 0, sizeof(dp));
32         memset(Max, 0, sizeof(Max));
33         for (int i = 1; i <= m; ++i)
34         {
35             mmax = -INF;
36             for (int j = i; j <= n; ++j)
37             {
38                 dp[j] = max(dp[j - 1] + arr[j], Max[j - 1] + arr[j]);
39                 Max[j - 1] = mmax;
40                 mmax = max(mmax, dp[j]);
41             }
42         }
43         printf("%d
", mmax);
44     }
45     return 0;
46 }