#include #include #include #include template struct ModInt { using lint = long long; int val; // constructor ModInt(lint v = 0) : val(v % MOD) { if (val < 0) val += MOD; }; // unary operator ModInt operator+() const { return ModInt(val); } ModInt operator-() const { return ModInt(MOD - val); } ModInt inv() const { return this->pow(MOD - 2); } // arithmetic ModInt operator+(const ModInt& x) const { return ModInt(*this) += x; } ModInt operator-(const ModInt& x) const { return ModInt(*this) -= x; } ModInt operator*(const ModInt& x) const { return ModInt(*this) *= x; } ModInt operator/(const ModInt& x) const { return ModInt(*this) /= x; } ModInt pow(lint n) const { auto x = ModInt(1); auto b = *this; while (n > 0) { if (n & 1) x *= b; n >>= 1; b *= b; } return x; } // compound assignment ModInt& operator+=(const ModInt& x) { if ((val += x.val) >= MOD) val -= MOD; return *this; } ModInt& operator-=(const ModInt& x) { if ((val -= x.val) < 0) val += MOD; return *this; } ModInt& operator*=(const ModInt& x) { val = lint(val) * x.val % MOD; return *this; } ModInt& operator/=(const ModInt& x) { return *this *= x.inv(); } // compare bool operator==(const ModInt& b) const { return val == b.val; } bool operator!=(const ModInt& b) const { return val != b.val; } bool operator<(const ModInt& b) const { return val < b.val; } bool operator<=(const ModInt& b) const { return val <= b.val; } bool operator>(const ModInt& b) const { return val > b.val; } bool operator>=(const ModInt& b) const { return val >= b.val; } // I/O friend std::istream& operator>>(std::istream& is, ModInt& x) noexcept { lint v; is >> v; x = v; return is; } friend std::ostream& operator<<(std::ostream& os, const ModInt& x) noexcept { return os << x.val; } }; template struct SegmentTree { using Merger = std::function; int length; std::vector dat; T unit; Merger merge; SegmentTree() = default; SegmentTree(int n, const T& unit, const Merger& merge) : length(1), unit(unit), merge(merge) { while (length < n) length <<= 1; dat.assign(length * 2, unit); } template SegmentTree(const Container& elems, const T& unit, const Merger& merge) : length(1), unit(unit), merge(merge) { int n = elems.size(); while (length < n) length <<= 1; dat.assign(length * 2, unit); std::copy(elems.begin(), elems.end(), dat.begin() + length); for (int nidx = length - 1; nidx >= 1; --nidx) { T vl = dat[nidx * 2 + 0]; T vr = dat[nidx * 2 + 1]; dat[nidx] = merge(vl, vr); } } void update(int nidx, const T& elem) { nidx += length; dat[nidx] = elem; while (nidx > 0) { nidx >>= 1; T vl = dat[nidx * 2 + 0]; T vr = dat[nidx * 2 + 1]; dat[nidx] = merge(vl, vr); } } T fold(int ql, int qr) const { ql = std::max(ql, 0); qr = std::min(qr, length); ql += length, qr += length; T lacc = unit, racc = unit; while (ql < qr) { if (ql & 1) { lacc = merge(lacc, dat[ql]); ++ql; } if (qr & 1) { --qr; racc = merge(dat[qr], racc); } ql >>= 1, qr >>= 1; } return merge(lacc, racc); } T get(int idx) const { return dat[idx + length]; } T fold_all() const { return dat[1]; } }; constexpr int MOD = 1000000007; using mint = ModInt; void solve() { int n, m; std::cin >> n >> m; std::vector nonzero(n + 2, 0); int nonzq = 0; std::vector ls(n + 1, -1); while (m--) { int l, r, p; std::cin >> l >> r >> p; if (p != 0) { ++nonzero[l]; --nonzero[r + 1]; ++nonzq; } else { ls[r] = l; } } int nonze = 0; for (int i = 1; i <= n; ++i) { if (nonzero[i]) ++nonze; nonzero[i + 1] += nonzero[i]; } mint pz = mint(2).pow(nonze - nonzq); SegmentTree seg(n + 1, 0, [](auto a, auto b) { return a + b; }); seg.update(0, 1); int l = 0, p = 0; for (int i = 1; i <= n; ++i) { if (nonzero[i] == 0) { seg.update(i, seg.fold(l, i) / mint(2)); ++p; } l = std::max(l, ls[i]); } mint po = seg.fold(l, n + 1) * mint(2).pow(p); std::cout << pz * po << "\n"; } int main() { std::cin.tie(nullptr); std::ios::sync_with_stdio(false); solve(); return 0; }