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
71
72
73
74
75
76
77
78
#include "maklib.h"
#include "message.h"
#include <cstdio>
#include <algorithm>
using namespace std;
typedef long long LL;

const int BEGIN = (MyNodeId() * Size()) / NumberOfNodes() + 1;
const int END = ((MyNodeId() + 1) * Size()) / NumberOfNodes() + 1;

LL res, w, left_res, middle_res, right_res, all_res;
	
void GetMiddle()
{
	w = 0;
	for (int i = BEGIN; i < END; ++i)
	{
		if (w > 0)
			w += ElementAt(i);
		else
			w = ElementAt(i);
		
		middle_res = max(w, middle_res);
	}
}

void GetLeft()
{
	w = 0;
	for (int i = BEGIN; i < END; ++i)
	{
		w += ElementAt(i);
		left_res = max(w, left_res);
	}
	all_res = w;
}

void GetRight()
{
	w = 0;
	for (int i = END-1; i >= BEGIN; --i)
	{
		w += ElementAt(i);
		right_res = max(w, right_res);
	}
}

int main ()
{
	GetLeft();
	GetMiddle();
	GetRight();
	
	if (MyNodeId() > 0)
	{
		PutLL(0, left_res);
		PutLL(0, middle_res);
		PutLL(0, right_res);
		PutLL(0, all_res);
		Send(0);
	}
	else
	{
		res = middle_res;
		w = right_res;
		for (int instance = 1; instance < NumberOfNodes(); ++instance)
		{
			Receive(instance);
			LL left = GetLL(instance);
			LL middle = GetLL(instance);
			LL right = GetLL(instance);
			LL all = GetLL(instance);
			res = max(middle, max(res, w + left));
			w = max(w + all, right);
		}
		printf ("%lld", res);
	}
}