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
#include <iostream>
#include <vector>
#include <tuple>
#include <math.h>
#include <algorithm>
#include <unordered_set>

using namespace std;

bool compare(unordered_set<int> v1, unordered_set<int> v2)
{
    return v1.size() > v2.size();
}


vector<unordered_set<int> > collisions(vector<tuple<int, int, int> > &x, vector<tuple<int, int, int> > &y, int n)
{
    vector < unordered_set<int> > ret(n);

    for (int i = 0; i < x.size(); i++)
    {
        int delay1 = get<1>(x[i]);
        int start1 = get<0>(x[i]);
        int index1 = get<2>(x[i]);

        for (int p = 0; p < y.size(); p++)
        {
            int delay2 = get<1>(y[p]);
            int start2 = get<0>(y[p]);
            int index2 = get<2>(y[p]);

            if (start1 - delay1 == start2 - delay2)
            {
                ret[index1].insert(index2);
                ret[index2].insert(index1);
            }
        }
    }

    return ret;
}

pair<int,int> findmaxindex(vector<unordered_set<int> > v)
{
    int indx = 0;
    int max = 0;
    for (int i = 0;i<v.size();i++)
    {
        if (v[i].size() > max)
        {
            indx = i;
            max = v[i].size();
       }
    }

    return { indx,max };
}

void remove(int x, vector<unordered_set<int> > &v)
{
    for (auto k : v[x])
    {
        v[k].erase(x);
    }
    v[x].clear();
    //sort(v.begin(), v.end(), compare);
}

void printv(vector<unordered_set<int> > v)
{
    for (auto k : v)
    {
        for (auto g : k)
        {
            cout << g << "  ";
        }
        cout << endl;
    }
}

int main()
{
    int n;
    cin >> n;
    vector<tuple<int,int,int> > x;
    vector<tuple<int,int,int> > y;

    for (int i = 0; i < n; i++)
    {
        int a, b, c;
        cin >> a >> b >> c;
        if (a == 1)
        {
            x.push_back({ b,c,i });
        }
        else
        {
            y.push_back({ b,c,i });
        }
    }

    vector<unordered_set<int> > v = collisions(x, y, n);
    pair<int, int> p = findmaxindex(v);

    int cnt = 0;
    //printv(v);
    while (p.second != 0)
    {
        //printv(v);
        remove(p.first, v);
        cnt++;
        p = findmaxindex(v);
    }
    cout << cnt;

    

}