1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
#include <bits/stdc++.h>
using namespace std;
typedef vector<int> VI;
typedef pair <int,int> ii;
typedef long long LL;
typedef pair <LL,LL> lp;
#define pb push_back
const int INF = 2147483647;
const int N = 205;

LL m, tab[N], sum[N][N], T[N][N][70], Q[N][N][70], act, rest, lastRest;
int n, i, j, d, u, l, k, lastK;

int main() {
scanf("%d %lld", &n, &m);
d = 0;
while ((1LL << d) <= m) d++;
for (i=1;i<=n;i++) scanf("%lld", &tab[i]);
for (i=1;i<=n;i++) {
	sum[i][i] = tab[i];
	for (j=i+1;j<=n;j++) sum[i][j] = sum[i][j - 1] + tab[j];
}
for (i=1;i<=n;i++) T[i][i][0] = Q[i][i][0] = 0;
k = 1;
rest = 1;
for (j=1;j<=d;j++) {
	lastK = k;
	k = min(k * 2, n);
	lastRest = rest;
	rest = (m + 1) % (1LL << j);
	if (rest == 0) rest = (1LL << j);
	for (i=1;i<=n;i++) {
		for (l=i;l<=min(n, i + k - 1);l++) {
			T[i][l][j] = -(1LL<<62);
			for (u=0;u <= l - i + 1;u++) if (u <= lastK && l - i + 1 - u <= lastK) {
				act = 0;
				if (u != 0) act += T[i][i + u - 1][j - 1];
				if (u != l - i + 1) {
					act += T[i + u][l][j - 1];
					act += sum[i + u][l];
				}
				T[i][l][j] = max(T[i][l][j], act);
			}
			
			if (rest == (1LL << j)) {
				Q[i][l][j] = T[i][l][j];
				continue;
			}			
			if (rest <= (1LL << (j - 1))) {
				Q[i][l][j] = Q[i][l][j - 1];
				continue;
			}
			if (l - i + 1 > rest) continue;	
			Q[i][l][j] = -(1LL<<62);
			for (u=0;u <= l - i + 1;u++) if (u <= lastK && l - i + 1 - u <= lastRest) {
				act = 0;
				if (u != 0) act += T[i][i + u - 1][j - 1];
				if (u != l - i + 1) {
					act += Q[i + u][l][j - 1];
					act += sum[i + u][l];
				}
				Q[i][l][j] = max(Q[i][l][j], act);
			}
			//printf("%d %d %d %lld\n", i, l, j, Q[i][l][j]);
		}
	}
}
printf("%lld\n", Q[1][n][d]);
return 0;
}