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
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
#include <iostream>
#include <vector>
#include <algorithm>

class Range {
public:

    int l;
    int r;

    Range(const int l, const int r) {
        this->l = l;
        this->r = r;
    }

    bool overlaps(const Range &that) const {
        return (l <= that.l && that.l <= r) || (that.l <= l && l <= that.r);
    }

    void join(const Range &range) {
        this->l = std::min(l, range.l);
        this->r = std::max(r, range.r);
    }

    bool compare(const Range &that) const {
        return l < that.l;
    }

    bool isSibling(const Range &that) const {
        return l - 1 == that.r || that.l - 1 == r;
    }

    int count() const {
        return r - l + 1;
    }

    bool isEmpty() const {
        return l == 0 && r == 0;
    }
} EMPTY = Range(0, 0);

bool compare(Range &r1, Range &r2) {
    return r1.compare(r2);
}

class Ranges {
    std::vector<Range> *ranges;
public:
    Ranges() {
        this->ranges = new std::vector<Range>();
    }

    void add(Range r) {
        ranges->push_back(r);
    }

    Ranges *compact() {
        if (!ranges->empty()) {
            std::sort(ranges->begin(), ranges->end(), compare);
            auto *newVector = new std::vector<Range>();
            newVector->push_back(ranges->front());
            auto iter = newVector->begin();
            for (auto it = ranges->begin() + 1; it != ranges->end(); ++it) {
                Range &currentOld = *it;
                if (iter->overlaps(currentOld) || iter->isSibling(currentOld)) {
                    iter->join(currentOld);
                } else {
                    newVector->push_back(currentOld);
                    iter = newVector->end() - 1;
                }
            }
            delete ranges;
            ranges = newVector;
        }
        return this;
    }

    Ranges *intersect(Ranges &other) {
        auto thisIt = this->ranges->begin();
        auto thatIt = other.ranges->begin();

        auto *newRanges = new Ranges();
        while (thisIt != this->ranges->end() && thatIt != other.ranges->end()) {
            if (thisIt->overlaps(*thatIt)) {
                newRanges->add(Range(std::max(thisIt->l, thatIt->l),
                                     std::min(thisIt->r, thatIt->r)));
            }
            if (thisIt->r < thatIt->r) {
                thisIt++;
            } else {
                thatIt++;
            }
        }
        return newRanges;
    }

    int diffCount(Ranges &other) {
        if (other.ranges->empty()) {
            return this->count();
        }
        if (this->ranges->empty()) {
            return 0;
        }

        auto thisIt = this->ranges->begin();
        auto thatIt = other.ranges->begin();

        Range rest = EMPTY;
        int count = 0;
        while (thisIt != this->ranges->end() && thatIt != other.ranges->end()) {

            if (rest.isEmpty()) {
                rest = *thisIt;
            }

            if (rest.r < thatIt->l) {
                count += rest.count();
                rest = EMPTY;
            } else if (thatIt->r < rest.l) {
                thatIt++;
            } else if (rest.l >= thatIt->l && rest.r <= thatIt->r) {
                rest = EMPTY;
            } else if (rest.l < thatIt->l) {
                count += Range(rest.l, thatIt->l - 1).count();
                if (thatIt->r < rest.r) {
                    rest = Range(thatIt->r + 1, rest.r);
                    thatIt++;
                } else if (thatIt->r == rest.r) {
                    rest = EMPTY;
                } else {
                    rest = EMPTY;
                }
            } else {
                rest = Range(thatIt->r + 1, rest.r);
                thatIt++;
            }

            if (rest.isEmpty()) {
                thisIt++;
            }
        }

        if (!rest.isEmpty()) {
            count += rest.count();
            thisIt++;
        }

        while (thisIt != ranges->end()) {
            count += (*thisIt).count();
            thisIt++;
        }

        return count;
    }

    int count() {
        int ret = 0;
        for (auto &range : *ranges) {
            ret += range.count();
        }
        return ret;
    }

//    void print() {
//        for (auto &range : *ranges) {
//            std::cout << "[" << range.l << "," << range.r << "]";
//        }
//        std::cout << std::endl;
//    }
};

int main() {
    std::ios_base::sync_with_stdio(0);
    int n;
    int m;
    int l;
    int r;
    int color;
    std::cin >> n >> m;

    Ranges colors[] = {Ranges(), Ranges(), Ranges()};
    for (int i = 0; i < m; i++) {
        std::cin >> l >> r >> color;
        colors[color - 1].add(Range(l, r));
    }
    colors[0].compact();
    colors[1].compact();
    colors[2].compact();
    Ranges *green = colors[0].intersect(colors[1]);
//    colors[0].print();
//    colors[1].print();
//    colors[2].print();
//    green->print();
//    green2->print();
    std::cout << green->diffCount(colors[2]) << std::endl;
    return 0;
}