Problem p02599 (C++) — buggy submission, verdict: Runtime Error

#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define ld long double
#define ar array

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;

template <typename T>
using oset =
    tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

#define vt vector
#define pb push_back
#define all(c) (c).begin(), (c).end()
#define sz(x) (int)(x).size()

#define F_OR(i, a, b, s)                                                       \\
  for (int i = (a); (s) > 0 ? i < (b) : i > (b); i += (s))
#define F_OR1(e) F_OR(i, 0, e, 1)
#define F_OR2(i, e) F_OR(i, 0, e, 1)
#define F_OR3(i, b, e) F_OR(i, b, e, 1)
#define F_OR4(i, b, e, s) F_OR(i, b, e, s)
#define GET5(a, b, c, d, e, ...) e
#define F_ORC(...) GET5(__VA_ARGS__, F_OR4, F_OR3, F_OR2, F_OR1)
#define FOR(...) F_ORC(__VA_ARGS__)(__VA_ARGS__)
#define EACH(x, a) for (auto &x : a)

template <class T> bool umin(T &a, const T &b) { return b < a ? a = b, 1 : 0; }
template <class T> bool umax(T &a, const T &b) { return a < b ? a = b, 1 : 0; }

ll FIRSTTRUE(function<bool(ll)> f, ll lb, ll rb) {
  while (lb < rb) {
    ll mb = (lb + rb) / 2;
    f(mb) ? rb = mb : lb = mb + 1;
  }
  return lb;
}
ll LASTTRUE(function<bool(ll)> f, ll lb, ll rb) {
  while (lb < rb) {
    ll mb = (lb + rb + 1) / 2;
    f(mb) ? lb = mb : rb = mb - 1;
  }
  return lb;
}

template <class A> void read(vt<A> &v);
template <class A, size_t S> void read(ar<A, S> &a);
template <class T> void read(T &x) { cin >> x; }
void read(double &d) {
  string t;
  read(t);
  d = stod(t);
}
void read(long double &d) {
  string t;
  read(t);
  d = stold(t);
}
template <class H, class... T> void read(H &h, T &...t) {
  read(h);
  read(t...);
}
template <class A> void read(vt<A> &x) {
  EACH(a, x)
  read(a);
}
template <class A, size_t S> void read(array<A, S> &x) {
  EACH(a, x)
  read(a);
}

string to_string(char c) { return string(1, c); }
string to_string(bool b) { return b ? "true" : "false"; }
string to_string(const char *s) { return string(s); }
string to_string(string s) { return s; }
string to_string(vt<bool> v) {
  string res;
  FOR(sz(v))
  res += char('0' + v[i]);
  return res;
}

template <size_t S> string to_string(bitset<S> b) {
  string res;
  FOR(S)
  res += char('0' + b[i]);
  return res;
}
template <class T> string to_string(T v) {
  bool f = 1;
  string res;
  EACH(x, v) {
    if (!f)
      res += ' ';
    f = 0;
    res += to_string(x);
  }
  return res;
}

template <class A> void write(A x) { cout << to_string(x); }
template <class H, class... T> void write(const H &h, const T &...t) {
  write(h);
  write(t...);
}
void print() { write("\\n"); }
template <class H, class... T> void print(const H &h, const T &...t) {
  write(h);
  if (sizeof...(t))
    write(' ');
  print(t...);
}

void DBG() { cerr << "]" << endl; }
template <class H, class... T> void DBG(H h, T... t) {
  cerr << to_string(h);
  if (sizeof...(t))
    cerr << ", ";
  DBG(t...);
}
#ifdef _DEBUG
#define dbg(...)                                                               \\
  cerr << "LINE(" << __LINE__ << ") -> [" << #__VA_ARGS__ << "]: [",           \\
      DBG(__VA_ARGS__)
#else
#define dbg(...) 0
#endif

template <class T> void offset(ll o, T &x) { x += o; }
template <class T> void offset(ll o, vt<T> &x) {
  EACH(a, x)
  offset(o, a);
}
template <class T, size_t S> void offset(ll o, ar<T, S> &x) {
  EACH(a, x)
  offset(o, a);
}

mt19937 mt_rng(chrono::steady_clock::now().time_since_epoch().count());
ll randint(ll a, ll b) { return uniform_int_distribution<ll>(a, b)(mt_rng); }

template <class T, class U> void vti(vt<T> &v, U x, size_t n) {
  v = vt<T>(n, x);
}
template <class T, class U> void vti(vt<T> &v, U x, size_t n, size_t m...) {
  v = vt<T>(n);
  EACH(a, v)
  vti(a, x, m);
}

const int d4i[4] = {-1, 0, 1, 0}, d4j[4] = {0, 1, 0, -1};
const int d8i[8] = {-1, -1, 0, 1, 1, 1, 0, -1},
          d8j[8] = {0, 1, 1, 1, 0, -1, -1, -1};

const int mxN = 5e5;
int n, q, c[mxN], ft[mxN + 1], ans[mxN];
vt<ar<int, 2>> v[mxN];

void upd(int i, int x) {
  for (++i; i <= n; i += i & -i)
    ft[i] += x;
}

int qry(int i) {
  int r = 0;
  for (; i; i -= i & -i)
    r += ft[i];
  return r;
}

void solve() {
  read(n, q);
  FOR(n)
  read(c[i]);
  FOR(q) {
    int l, r;
    read(l, r), --l, --r;
    v[r].pb({l, i});
  }
  map<int, int> mp;
  FOR(n) {
    if (mp.find(c[i]) != mp.end())
      upd(mp[c[i]], -1);
    upd(i, 1);
    EACH(a, v[i])
    ans[a[1]] = qry(n) - qry(a[0]);
    mp[c[i]] = i;
  }
  FOR(q)
  print(ans[i]);
}

int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);

  int t = 1;
  // read(t);
  FOR(t) {
    // write("Case #", i+1, ": ");
    solve();
  }
}


Error: 0

Fixed submission:

#include <bits/stdc++.h>
using namespace std;

// Each segment of the segment tree would be a set
// to maintain distinct elements
set<int> *segment;

// Build the segment tree
// i denotes current node, s denotes start and
// e denotes the end of range for current node
void build(int i, int s, int e, int arr[]) {

  // If start is equal to end then
  // insert the array element
  if (s == e) {
    segment[i].insert(arr[s]);
    return;
  }

  // Else divide the range into two halves
  // (start to mid) and (mid+1 to end)
  // first half will be the left node
  // and the second half will be the right node
  build(2 * i, s, (s + e) / 2, arr);
  build(1 + 2 * i, 1 + (s + e) / 2, e, arr);

  segment[i].insert(segment[2 * i].begin(), segment[2 * i].end());

  segment[i].insert(segment[2 * i + 1].begin(), segment[2 * i + 1].end());
}

// Query in an range a to b
set<int> query(int node, int l, int r, int a, int b) {
  set<int> left, right, result;

  // If the range is out of the bounds
  // of this segment
  if (b < l || a > r)
    return result;

  // If the range lies in this segment
  if (a <= l && r <= b)
    return segment[node];

  left = query(2 * node, l, (l + r) / 2, a, b);
  result.insert(left.begin(), left.end());

  right = query(1 + 2 * node, 1 + (l + r) / 2, r, a, b);
  result.insert(right.begin(), right.end());

  // Return the result
  return result;
}

// Initialize the segment tree
void init(int n) {
  // Get the height of the segment tree
  int h = (int)ceil(log2(n));
  h = (2 * (pow(2, h))) - 1;

  // Initialize the segment tree
  segment = new set<int>[h];
}

void getDistinct(int l, int r, int n) {
  set<int> ans = query(1, 0, n - 1, l, r);

  cout << ans.size() << endl;
}

// Driver code
int main() {
  int n, q;
  cin >> n >> q;
  int arr[n];
  for (int i = 0; i < n; i++) {
    cin >> arr[i];
    arr[i]--;
  }

  init(n);

  build(1, 0, n - 1, arr);
  while (q--) {
    int l, r;
    cin >> l >> r;
    getDistinct(l - 1, r - 1, n);
  }

  return 0;
}