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
#include <algorithm>
#include <set>
#include <stdio.h>

template <typename T>
class interval_tree
{
public:
	struct interval
	{
		T min;
		T max;

		bool operator<(const interval &i) const
		{
			return min < i.min;
		}
	};

	void merge(const interval i)
	{
		auto it = m_data.lower_bound(i);
		while (it != m_data.end() && i.min <= it->min && it->max <= i.max)
		{
			m_data.erase(it);
			it = m_data.lower_bound(i);
		}

		const auto left = find(i.min - 1);
		const auto right = find(i.max + 1);
		const auto left_contains = contains(i.min - 1, left);
		const auto right_contains = contains(i.max + 1, right);
		if (left_contains && right_contains)
		{
			m_data.erase(left);
			if (left != right)
				m_data.erase(right);
			m_data.insert({left->min, right->max});
		}
		else if (left_contains)
		{
			m_data.erase(left);
			m_data.insert({left->min, i.max});
		}
		else if (right_contains)
		{
			m_data.erase(right);
			m_data.insert({i.min, right->max});
		}
		else
		{
			m_data.insert(i);
		}
	}

	bool contains(const T &value)
	{
		return contains(value, find(value));
	}

private:
	typename std::set<interval>::iterator find(const T value)
	{
		auto index = m_data.lower_bound({value, value});
		if (index == m_data.end())
		{
			if (index != m_data.begin())
				index--;
		}
		else if (index->min != value)
		{
			if (index != m_data.begin())
				index--;
		}
		return index;
	}

	bool contains(const T value, typename std::set<interval>::iterator index)
	{
		return index != m_data.end() && index->min <= value && value <= index->max;
	}

	std::set<interval> m_data;
};

int main()
{
	interval_tree<int> y, b, r;
	int n, m, left, right, color;
	scanf("%d %d", &n, &m);
	for (int i = 0; i < m; ++i)
	{
		scanf("%d %d %d", &left, &right, &color);
		if (color == 1)
			y.merge({left, right});
		else if (color == 2)
			b.merge({left, right});
		else if (color == 3)
			r.merge({left, right});
	}
	int sum = 0;
	for (int i = 1; i <= n; ++i)
		if (y.contains(i) && b.contains(i) && !r.contains(i))
			sum++;
	printf("%d\n", sum);
	return 0;
}