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
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
#include <iostream>
#include <vector>

#include "message.h"
#include "teatr.h"

using namespace std;

long long inversions = 0;
vector<int> arr;

void realMerge(vector<int> &toMerge, int lStart, int lEnd, int rEnd) {
    int leftPos = lStart, rightPos = lEnd + 1;
    vector<int> merged;

    while (leftPos <= lEnd || rightPos <= rEnd) {
        if (leftPos <= lEnd) {
                if (rightPos <= rEnd) {
                    if (toMerge[leftPos] <= toMerge[rightPos]) {
                        merged.push_back(toMerge[leftPos]);
                        leftPos++;
                    } else {
                        inversions += lEnd - leftPos + 1;

                        merged.push_back(toMerge[rightPos]);
                        rightPos++;
                    }
                } else {
                    merged.push_back(toMerge[leftPos]);
                    leftPos++;
                }
        } else {
            merged.push_back(toMerge[rightPos]);
            rightPos++;
        }
    }

    for (unsigned int i = 0; i < merged.size(); i++) {
        toMerge[lStart + i] = merged[i];
    }
}

void merge(vector<int> &toSort, unsigned int start, unsigned int end) {
    if (start == end) {
        return;
    }

    unsigned int leftPos = start, rightPos = start + (end - start) / 2 + 1;
    merge(toSort, start, rightPos - 1);
    merge(toSort, rightPos, end);

    realMerge(toSort, leftPos, rightPos - 1, end);
}

void mergeSort(vector<int> &toSort) {
    merge(toSort, 0, (unsigned int)toSort.size() - 1);
}

void sendInfo(int target) {
    PutLL(target, inversions);

    PutInt(target, (int)arr.size());
    for (auto elem : arr) {
        PutInt(target, elem);
    }

    Send(target);
}

void getInfo(int source) {
    Receive(source);
    inversions += GetLL(source);

    int size = GetInt(source);
    for (int i = 0; i < size; i++) {
        arr.push_back(GetInt(source));
    }

    realMerge(arr, 0, (int)arr.size() - size - 1, (int)arr.size() - 1);
}

int main() {
    ios_base::sync_with_stdio(0);

    int id = MyNodeId();
    int start = id * 1000000, end = start + 1000000 - 1;

    if (start > GetN() - 1) {
        return 0;
    }

    for (int i = start; i <= min(GetN() - 1, end); i++) {
        arr.push_back(GetElement(i));
    }

    mergeSort(arr);

    // communication
    int whoSend = 2, level = 1;

    while (true) {
        if (arr.size() == GetN() && id == 0) {
            break;
        }

        if ((id - level) % whoSend == 0) {
            // has to send
            sendInfo(id - level);
            break;
        } else {
            if (start + arr.size() != GetN()) {
                // get info only if missing
                getInfo(id + level);
            }
        }

        whoSend *= 2;
        level *= 2;
    }


    if (id == 0) {
        cout << inversions << "\n";
    }

    return 0;
}