Problem p03182 (C++)

Buggy submission (status: Time Limit Exceeded):
#pragma region Macros
#pragma GCC optimize("O3")
#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define rep2(i, a, b) for (ll i = a; i <= b; ++i)
#define rep(i, n) for (ll i = 0; i < n; i++)
#define rep3(i, a, b) for (ll i = a; i >= b; i--)
#define pii pair<int, int>
#define pll pair<ll, ll>
#define pq priority_queue
#define pb push_back
#define eb emplace_back
#define vec vector<int>
#define vecll vector<ll>
#define vecpii vector<pii>
#define vec2(a, b) vector<vec>(a, vec(b))
#define vec2ll(a, b) vector<vecll>(a, vecll(b))
#define vec3(a, b, c) vector<vector<vec>>(a, vec2(b, c))
#define vec3ll(a, b, c) vector<vector<vecll>>(a, vec2ll(b, c))
#define fi first
#define se second
#define endl "\n"
#define all(c) begin(c), end(c)
#define ios ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
#define lb(c, x) distance(c.begin(), lower_bound(all(c), (x)))
#define ub(c, x) distance(c.begin(), upper_bound(all(c), (x)))
using namespace std;
int in() {
  int x;
  cin >> x;
  return x;
}
ll lin() {
  ll x;
  cin >> x;
  return x;
}
string stin() {
  string s;
  cin >> s;
  return s;
}
template <class T> inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}
vec iota(int n) {
  vec a(n);
  iota(all(a), 0);
  return a;
}
void print() { putchar(' '); }
void print(bool a) { cout << a; }
void print(int a) { cout << a; }
void print(long long a) { cout << a; }
void print(char a) { cout << a; }
void print(string &a) { cout << a; }
void print(double a) { cout << a; }
template <class T> void print(const vector<T> &);
template <class T, size_t size> void print(const array<T, size> &);
template <class T, class L> void print(const pair<T, L> &p);
template <class T, size_t size> void print(const T (&)[size]);
template <class T> void print(const vector<T> &a) {
  if (a.empty())
    return;
  print(a[0]);
  for (auto i = a.begin(); ++i != a.end();) {
    cout << " ";
    print(*i);
  }
}
template <class T> void print(const deque<T> &a) {
  if (a.empty())
    return;
  print(a[0]);
  for (auto i = a.begin(); ++i != a.end();) {
    cout << " ";
    print(*i);
  }
}
template <class T, size_t size> void print(const array<T, size> &a) {
  print(a[0]);
  for (auto i = a.begin(); ++i != a.end();) {
    cout << " ";
    print(*i);
  }
}
template <class T, class L> void print(const pair<T, L> &p) {
  cout << '(';
  print(p.first);
  cout << ",";
  print(p.second);
  cout << ')';
}
template <class T, size_t size> void print(const T (&a)[size]) {
  print(a[0]);
  for (auto i = a; ++i != end(a);) {
    cout << " ";
    print(*i);
  }
}
template <class T> void print(const T &a) { cout << a; }
int out() {
  putchar('\n');
  return 0;
}
template <class T> int out(const T &t) {
  print(t);
  putchar('\n');
  return 0;
}
template <class Head, class... Tail>
int out(const Head &head, const Tail &...tail) {
  print(head);
  putchar(' ');
  out(tail...);
  return 0;
}
ll gcd(ll a, ll b) {
  while (b) {
    ll c = b;
    b = a % b;
    a = c;
  }
  return a;
}
ll lcm(ll a, ll b) {
  if (!a || !b)
    return 0;
  return a * b / gcd(a, b);
}
#define _GLIBCXX_DEBU
#ifdef _MY_DEBUG
#undef endl
#define debug(x) cout << #x << ": " << x << endl
void err() {}
template <class T> void err(const T &t) {
  print(t);
  cout << " ";
}
template <class Head, class... Tail>
void err(const Head &head, const Tail &...tail) {
  print(head);
  putchar(' ');
  out(tail...);
}
#else
#define debug(x)
template <class... T> void err(const T &...) {}
#endif
#pragma endregion

template <typename T, typename E> struct LazySegmentTree {
  typedef function<T(T, T)> F;
  typedef function<T(T, E)> G;
  typedef function<E(E, E)> H;
  typedef function<E(E, int)> P;
  int n;
  F f;
  G g;
  H h;
  P p;
  T d1;
  E d0;
  vector<T> dat;
  vector<E> laz;
  LazySegmentTree(
      int n_, F f, G g, H h, T d1, E d0, vector<T> v = vector<T>(),
      P p = [](E a, int b) { return a; })
      : f(f), g(g), h(h), d1(d1), d0(d0), p(p) {
    init(n_);
    if (n_ == (int)v.size())
      build(n_, v);
  }
  void init(int n_) {
    n = 1;
    while (n < n_)
      n *= 2;
    dat.clear();
    dat.resize(2 * n - 1, d1);
    laz.clear();
    laz.resize(2 * n - 1, d0);
  }
  void build(int n_, vector<T> v) {
    for (int i = 0; i < n_; i++)
      dat[i + n - 1] = v[i];
    for (int i = n - 2; i >= 0; i--)
      dat[i] = f(dat[i * 2 + 1], dat[i * 2 + 2]);
  }
  inline void eval(int len, int k) {
    if (laz[k] == d0)
      return;
    if (k * 2 + 1 < n * 2 - 1) {
      laz[k * 2 + 1] = h(laz[k * 2 + 1], laz[k]);
      laz[k * 2 + 2] = h(laz[k * 2 + 2], laz[k]);
    }
    dat[k] = g(dat[k], p(laz[k], len));
    laz[k] = d0;
  }
  T update(int a, int b, E x, int k, int l, int r) {
    eval(r - l, k);
    if (r <= a || b <= l)
      return dat[k];
    if (a <= l && r <= b) {
      laz[k] = h(laz[k], x);
      return g(dat[k], p(laz[k], r - l));
    }
    return dat[k] = f(update(a, b, x, k * 2 + 1, l, (l + r) / 2),
                      update(a, b, x, k * 2 + 2, (l + r) / 2, r));
  }
  T update(int a, int b, E x) { return update(a, b, x, 0, 0, n); }
  T query(int a, int b, int k, int l, int r) {
    eval(r - l, k);
    if (r <= a || b <= l)
      return d1;
    if (a <= l && r <= b)
      return dat[k];
    T vl = query(a, b, k * 2 + 1, l, (l + r) / 2);
    T vr = query(a, b, k * 2 + 2, (l + r) / 2, r);
    return f(vl, vr);
  }
  T query(int a, int b) { return query(a, b, 0, 0, n); }
};

constexpr int N = 301000;

// 区間加算区間和

signed main() {
  ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
  cout << fixed << setprecision(15);
  int n = in(), m = in();
  vector<vecpii> a(n + 2);
  vecll r(n + 2);
  LazySegmentTree<ll, ll> seg(
      N, [](ll x, ll y) { return max(x, y); }, plus<ll>(), plus<ll>(),
      -LONG_LONG_MAX, 0);
  seg.build(n + 2, vecll(n + 2));
  rep(i, m) {
    int x = in(), y = in();
    ll c = in();
    seg.update(x, y + 1, -c);
    a[y + 1].eb(x, c);
    r[x] += c;
    r[y + 1] -= c;
  }
  rep(i, n + 1) r[i + 1] += r[i];
  vecll dp(n + 1);
  rep2(i, 1, n) {
    for (auto e : a[i]) {
      seg.update(e.fi, i, e.se);
    }
    rep2(i, 1, n) err(seg.query(i, i + 1));
    dp[i] = r[i] + seg.query(0, i);
    seg.update(i, i + 1, dp[i]);
  }
  cout << *max_element(all(dp)) << endl;
}


Fixed submission:
#pragma region Macros
#pragma GCC optimize("O3")
#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define rep2(i, a, b) for (ll i = a; i <= b; ++i)
#define rep(i, n) for (ll i = 0; i < n; i++)
#define rep3(i, a, b) for (ll i = a; i >= b; i--)
#define pii pair<int, int>
#define pll pair<ll, ll>
#define pq priority_queue
#define pb push_back
#define eb emplace_back
#define vec vector<int>
#define vecll vector<ll>
#define vecpii vector<pii>
#define vec2(a, b) vector<vec>(a, vec(b))
#define vec2ll(a, b) vector<vecll>(a, vecll(b))
#define vec3(a, b, c) vector<vector<vec>>(a, vec2(b, c))
#define vec3ll(a, b, c) vector<vector<vecll>>(a, vec2ll(b, c))
#define fi first
#define se second
#define endl "\n"
#define all(c) begin(c), end(c)
#define ios ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
#define lb(c, x) distance(c.begin(), lower_bound(all(c), (x)))
#define ub(c, x) distance(c.begin(), upper_bound(all(c), (x)))
using namespace std;
int in() {
  int x;
  cin >> x;
  return x;
}
ll lin() {
  ll x;
  cin >> x;
  return x;
}
string stin() {
  string s;
  cin >> s;
  return s;
}
template <class T> inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}
vec iota(int n) {
  vec a(n);
  iota(all(a), 0);
  return a;
}
void print() { putchar(' '); }
void print(bool a) { cout << a; }
void print(int a) { cout << a; }
void print(long long a) { cout << a; }
void print(char a) { cout << a; }
void print(string &a) { cout << a; }
void print(double a) { cout << a; }
template <class T> void print(const vector<T> &);
template <class T, size_t size> void print(const array<T, size> &);
template <class T, class L> void print(const pair<T, L> &p);
template <class T, size_t size> void print(const T (&)[size]);
template <class T> void print(const vector<T> &a) {
  if (a.empty())
    return;
  print(a[0]);
  for (auto i = a.begin(); ++i != a.end();) {
    cout << " ";
    print(*i);
  }
}
template <class T> void print(const deque<T> &a) {
  if (a.empty())
    return;
  print(a[0]);
  for (auto i = a.begin(); ++i != a.end();) {
    cout << " ";
    print(*i);
  }
}
template <class T, size_t size> void print(const array<T, size> &a) {
  print(a[0]);
  for (auto i = a.begin(); ++i != a.end();) {
    cout << " ";
    print(*i);
  }
}
template <class T, class L> void print(const pair<T, L> &p) {
  cout << '(';
  print(p.first);
  cout << ",";
  print(p.second);
  cout << ')';
}
template <class T, size_t size> void print(const T (&a)[size]) {
  print(a[0]);
  for (auto i = a; ++i != end(a);) {
    cout << " ";
    print(*i);
  }
}
template <class T> void print(const T &a) { cout << a; }
int out() {
  putchar('\n');
  return 0;
}
template <class T> int out(const T &t) {
  print(t);
  putchar('\n');
  return 0;
}
template <class Head, class... Tail>
int out(const Head &head, const Tail &...tail) {
  print(head);
  putchar(' ');
  out(tail...);
  return 0;
}
ll gcd(ll a, ll b) {
  while (b) {
    ll c = b;
    b = a % b;
    a = c;
  }
  return a;
}
ll lcm(ll a, ll b) {
  if (!a || !b)
    return 0;
  return a * b / gcd(a, b);
}
#define _GLIBCXX_DEBU
#ifdef _MY_DEBUG
#undef endl
#define debug(x) cout << #x << ": " << x << endl
void err() {}
template <class T> void err(const T &t) {
  print(t);
  cout << " ";
}
template <class Head, class... Tail>
void err(const Head &head, const Tail &...tail) {
  print(head);
  putchar(' ');
  out(tail...);
}
#else
#define debug(x)
template <class... T> void err(const T &...) {}
#endif
#pragma endregion

template <typename T, typename E> struct LazySegmentTree {
  typedef function<T(T, T)> F;
  typedef function<T(T, E)> G;
  typedef function<E(E, E)> H;
  typedef function<E(E, int)> P;
  int n;
  F f;
  G g;
  H h;
  P p;
  T d1;
  E d0;
  vector<T> dat;
  vector<E> laz;
  LazySegmentTree(
      int n_, F f, G g, H h, T d1, E d0, vector<T> v = vector<T>(),
      P p = [](E a, int b) { return a; })
      : f(f), g(g), h(h), d1(d1), d0(d0), p(p) {
    init(n_);
    if (n_ == (int)v.size())
      build(n_, v);
  }
  void init(int n_) {
    n = 1;
    while (n < n_)
      n *= 2;
    dat.clear();
    dat.resize(2 * n - 1, d1);
    laz.clear();
    laz.resize(2 * n - 1, d0);
  }
  void build(int n_, vector<T> v) {
    for (int i = 0; i < n_; i++)
      dat[i + n - 1] = v[i];
    for (int i = n - 2; i >= 0; i--)
      dat[i] = f(dat[i * 2 + 1], dat[i * 2 + 2]);
  }
  inline void eval(int len, int k) {
    if (laz[k] == d0)
      return;
    if (k * 2 + 1 < n * 2 - 1) {
      laz[k * 2 + 1] = h(laz[k * 2 + 1], laz[k]);
      laz[k * 2 + 2] = h(laz[k * 2 + 2], laz[k]);
    }
    dat[k] = g(dat[k], p(laz[k], len));
    laz[k] = d0;
  }
  T update(int a, int b, E x, int k, int l, int r) {
    eval(r - l, k);
    if (r <= a || b <= l)
      return dat[k];
    if (a <= l && r <= b) {
      laz[k] = h(laz[k], x);
      return g(dat[k], p(laz[k], r - l));
    }
    return dat[k] = f(update(a, b, x, k * 2 + 1, l, (l + r) / 2),
                      update(a, b, x, k * 2 + 2, (l + r) / 2, r));
  }
  T update(int a, int b, E x) { return update(a, b, x, 0, 0, n); }
  T query(int a, int b, int k, int l, int r) {
    eval(r - l, k);
    if (r <= a || b <= l)
      return d1;
    if (a <= l && r <= b)
      return dat[k];
    T vl = query(a, b, k * 2 + 1, l, (l + r) / 2);
    T vr = query(a, b, k * 2 + 2, (l + r) / 2, r);
    return f(vl, vr);
  }
  T query(int a, int b) { return query(a, b, 0, 0, n); }
};

constexpr int N = 301000;

// 区間加算区間和

signed main() {
  ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
  cout << fixed << setprecision(15);
  int n = in(), m = in();
  vector<vecpii> a(n + 2);
  vecll r(n + 2);
  LazySegmentTree<ll, ll> seg(
      N, [](ll x, ll y) { return max(x, y); }, plus<ll>(), plus<ll>(),
      -LONG_LONG_MAX, 0);
  seg.build(n + 2, vecll(n + 2));
  rep(i, m) {
    int x = in(), y = in();
    ll c = in();
    seg.update(x, y + 1, -c);
    a[y + 1].eb(x, c);
    r[x] += c;
    r[y + 1] -= c;
  }
  rep(i, n + 1) r[i + 1] += r[i];
  vecll dp(n + 1);
  rep2(i, 1, n) {
    for (auto e : a[i]) {
      seg.update(e.fi, i, e.se);
    }
    dp[i] = r[i] + seg.query(0, i);
    seg.update(i, i + 1, dp[i]);
  }
  cout << *max_element(all(dp)) << endl;
}