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 <cstdio>
#include <cstring>
#include <cstdlib>
#include <cmath>
#include <vector>
#include <list>
#include <queue>
#include <set>
#include <map>
#include <numeric>
#include <utility>
#include <string>
#include <sstream>
#include <algorithm>

#include "message.h"
#include "maklib.h"

using namespace std;

void computePart(int begin, int end, long long &in, long long &out, long long &left, long long &right ) {
  in = out = left = right = 0LL;
  long long r = 0LL;
  for (int i = begin; i < end; ++i) {
    int v = ElementAt(i);
    out += v;
    left = max(left, out);
    r += v;
    r = max(r, 0LL);
    in = max(in, r);
  }
  right = r;
}

int main() {
  int nn = NumberOfNodes();
  int id = MyNodeId();
  int n = Size();

  long long in, out, left, right;
  int m = (n + nn - 1) / nn;
  int begin = id * m;
  int end = min(n, (id + 1) * m);
  computePart(begin, end, in, out, left, right); 
  if (id < nn - 1) {
    PutLL(nn - 1, in);
    PutLL(nn - 1, out);
    PutLL(nn - 1, left);
    PutLL(nn - 1, right);
    Send(nn - 1);
  } else {
    long long current = 0;
    long long ret = 0;
    for (int i = 0; i < nn - 1; ++i) {
      Receive(i);
      long long in = GetLL(i);
      long long out = GetLL(i);
      long long left = GetLL(i);
      long long right = GetLL(i);
      ret = max(ret, in);
      ret = max(ret, current + left);
      current = max(current + out, right);
    }
    ret = max(ret, in);
    ret = max(ret, current + left);
    current = max(current + out, right);
    printf("%lld\n", ret);
  }
  return 0;
}