Problem p02345 (C++)

Buggy submission (status: Runtime Error):
#include <bits/stdc++.h>
using namespace std;
#define int long long
using ll = long long;
using vi = vector<int>;
using vl = vector<long long>;
using pii = pair<int, int>;
using pll = pair<long long, long long>;
#define ITR(i, c) for (auto i = begin(c); i != end(c); ++i)
#define FORE(x, c) for (auto &x : c)
#define FOR(i, a, n) for (int i = a, i##_len = (int)(n); i < i##_len; ++i)
#define REP(i, n) FOR(i, 0, n)
#define RREP(i, n) for (int i = (int)(n); i >= 0; --i)
#define ALL(c) begin(c), end(c)
#define RALL(c) rbegin(c), rend(c) // c++14
#define SZ(c) ((int)c.size())
#define EXIST(c, x) (c.find(x) != end(c))
#define dump(...)
const int DX[9] = {0, 1, 0, -1, 1, 1, -1, -1, 0},
          DY[9] = {-1, 0, 1, 0, -1, 1, 1, -1, 0};
#define INF (1001001001)
#define INFLL (1001001001001001001ll)
template <class T> ostream &operator<<(ostream &os, const vector<T> &v) {
  ITR(i, v) os << *i << (i == end(v) - 1 ? "" : " ");
  return os;
}
template <class T> istream &operator>>(istream &is, vector<T> &v) {
  ITR(i, v) is >> *i;
  return is;
}
template <class T> istream &operator>>(istream &is, pair<T, T> &p) {
  is >> p.first >> p.second;
  return is;
}
template <class T> bool chmax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> bool chmin(T &a, const T &b) {
  if (b < a) {
    a = b;
    return 1;
  }
  return 0;
}
//------------------------------------------------------------------------------
struct before_main_function {
  before_main_function() {
#ifdef int
#undef INF
#define INF INFLL
#define stoi stoll
    cerr << "\x1b[7m"
         << "'int' is 'long long'"
         << "\x1b[m" << endl;
#endif
    cin.tie(0);
    ios::sync_with_stdio(false);
    cout << setprecision(15) << fixed;
  }
} before_main_function;
//------------------------------------------------------------------------------

struct RMQ {
  int n;
  vector<int> dat;
  RMQ(int n_ = 0) {
    n = 1;
    while (n < n_)
      n *= 2;
    dat = vector<int>(n * 2 - 1, 2147483647);
  }
  void update(int i, int x) {
    i += n - 1;
    dat[i] = x;
    while (i > 0) {
      i = (i - 1) / 2;
      dat[i] = min(dat[i * 2 + 1], dat[i * 2 + 2]);
    }
  }
  int query(int a, int b) { return query(a, b, 0, 0, n); }
  int query(int a, int b, int k, int l, int r) {
    if (r <= a or b <= l)
      return 2147483647;
    if (a <= l and r <= b)
      return dat[k];
    int ml = query(a, b, k * 2 + 1, l, (r + l) / 2);
    int mr = query(a, b, k * 2 + 2, (r + l) / 2, r);
    return min(ml, mr);
  }
};
signed main() {
  int n, q;
  cin >> n >> q;
  RMQ segtree(n);
  while (q--) {
    int com, x, y;
    cin >> com >> x >> y;
    if (com == 0) {
      segtree.update(x, y);
    } else {
      cout << segtree.query(x, y + 1) << endl;
    }
  }
  return 0;
}

Fixed submission:
#include <bits/stdc++.h>
using namespace std;
#define int long long
using ll = long long;
using vi = vector<int>;
using vl = vector<long long>;
using pii = pair<int, int>;
using pll = pair<long long, long long>;
#define ITR(i, c) for (auto i = begin(c); i != end(c); ++i)
#define FORE(x, c) for (auto &x : c)
#define FOR(i, a, n) for (int i = a, i##_len = (int)(n); i < i##_len; ++i)
#define REP(i, n) FOR(i, 0, n)
#define RREP(i, n) for (int i = (int)(n); i >= 0; --i)
#define ALL(c) begin(c), end(c)
#define RALL(c) rbegin(c), rend(c) // c++14
#define SZ(c) ((int)c.size())
#define EXIST(c, x) (c.find(x) != end(c))
#define dump(...)
const int DX[9] = {0, 1, 0, -1, 1, 1, -1, -1, 0},
          DY[9] = {-1, 0, 1, 0, -1, 1, 1, -1, 0};
#define INF (1001001001)
#define INFLL (1001001001001001001ll)
template <class T> ostream &operator<<(ostream &os, const vector<T> &v) {
  ITR(i, v) os << *i << (i == end(v) - 1 ? "" : " ");
  return os;
}
template <class T> istream &operator>>(istream &is, vector<T> &v) {
  ITR(i, v) is >> *i;
  return is;
}
template <class T> istream &operator>>(istream &is, pair<T, T> &p) {
  is >> p.first >> p.second;
  return is;
}
template <class T> bool chmax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> bool chmin(T &a, const T &b) {
  if (b < a) {
    a = b;
    return 1;
  }
  return 0;
}
//------------------------------------------------------------------------------
// struct before_main_function {
//     before_main_function() {
//         #ifdef int
//             #undef INF
//             #define INF INFLL
//             #define stoi stoll
//             cerr<<"\x1b[7m"<<"'int' is 'long long'"<<"\x1b[m"<<endl;
//         #endif
//         cin.tie(0);ios::sync_with_stdio(false);
//         cout<<setprecision(15)<<fixed;
//     }
// } before_main_function;
//------------------------------------------------------------------------------

struct RMQ {
  int n;
  vector<int> dat;
  RMQ(int n_ = 0) {
    n = 1;
    while (n < n_)
      n *= 2;
    dat = vector<int>(n * 2 - 1, 2147483647);
  }
  void update(int i, int x) {
    i += n - 1;
    dat[i] = x;
    while (i > 0) {
      i = (i - 1) / 2;
      dat[i] = min(dat[i * 2 + 1], dat[i * 2 + 2]);
    }
  }
  int query(int a, int b) { return query(a, b, 0, 0, n); }
  int query(int a, int b, int k, int l, int r) {
    if (r <= a or b <= l)
      return 2147483647;
    if (a <= l and r <= b)
      return dat[k];
    int ml = query(a, b, k * 2 + 1, l, (r + l) / 2);
    int mr = query(a, b, k * 2 + 2, (r + l) / 2, r);
    return min(ml, mr);
  }
};
signed main() {
  int n, q;
  cin >> n >> q;
  RMQ segtree(n);
  while (q--) {
    int com, x, y;
    cin >> com >> x >> y;
    if (com == 0) {
      segtree.update(x, y);
    } else {
      cout << segtree.query(x, y + 1) << endl;
    }
  }
  return 0;
}