Problem p03819 (C++)

Buggy submission (status: Time Limit Exceeded):
#include <algorithm>
#include <bitset>
#include <cmath>
#include <complex>
#include <deque>
#include <fstream>
#include <iostream>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <time.h>
#include <vector>

using std::cerr;
using std::cin;
using std::cout;
using std::endl;

using std::bitset;
using std::complex;
using std::deque;
using std::iterator;
using std::map;
using std::multimap;
using std::multiset;
using std::pair;
using std::queue;
using std::set;
using std::stack;
using std::string;
using std::vector;

using std::fill;
using std::ios_base;
using std::max_element;
using std::min_element;
using std::reverse;
using std::sort;
using std::stable_sort;
using std::swap;
using std::unique;

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<long long> vl;
typedef string S;
typedef complex<double> cd;

inline ll max(ll a, ll b) {
  if (a > b)
    return a;
  return b;
}

inline ll min(ll a, ll b) {
  if (a < b)
    return a;
  return b;
}

namespace MySpace {
struct Small_Segment_Tree {
  vector<int> a;
  int l, r;

private:
  int __summ(int L, int R, int l, int r, int v) {
    if (L <= l && r <= R)
      return a[v];
    if (R <= l || r <= L)
      return 0;
    int m = (l + r) / 2;
    return __summ(L, R, l, m, 2 * v + 1) + __summ(L, R, m, r, 2 * v + 2);
  }

  void __set(int P, int l, int r, int v, int V) {
    if (l + 1 == r) {
      a[v] = V;
      return;
    }
    int m = (l + r) / 2;
    if (P < m) {
      __set(P, l, m, 2 * v + 1, V);
      a[v] = a[2 * v + 1] + a[2 * v + 2];
    } else {
      __set(P, m, r, 2 * v + 2, V);
      a[v] = a[2 * v + 1] + a[2 * v + 2];
    }
  }

public:
  int Summ(int L, int R) {
    if (R < L)
      return 0;
    return __summ(L, R + 1, l, r, 0);
  }

  void Set(int P, int V) { __set(P, l, r, 0, V); }

  Small_Segment_Tree(int _n) {
    a.resize(4 * _n);
    l = 0, r = _n;
  }
};
long long inq(long long x, long long q, long long MOD) {
  if (q == 0)
    return 1;
  long long l = inq(x, q / 2, MOD);
  if (q % 2)
    return l * l % MOD * x % MOD;
  return l * l % MOD;
}
}; // namespace MySpace

using namespace MySpace;

#define F(i, n) for (int(i) = 0; (i) != (n); (i)++)
#define fi first
#define se second
#define re return
#define all(x) (x).begin(), (x).end()

const ll MOD = 1e9 + 7;
const ll K = 320;

ll n, m;
ll scan[500000];

int main() {
  ios_base::sync_with_stdio();
  cin.tie(0);
  cout.tie(0);
  cin >> n >> m;
  for (int i = 0; i < n; i++) {
    int l, r;
    cin >> l >> r;
    l--;
    vector<pair<int, int>> psar;
    for (int j = 1; j <= K; j++) {
      if (r / j != l / j) {
        // cout << l << " " << r << " : " << l / j << " " << r / j << " " << j
        // << endl;
        scan[j]++;
        scan[j + 1]--;
        int left = l / j + 1;
        int right = r / j;
        left = max(left, K + 1);
        if (right < K + 1)
          continue;
        psar.push_back({left, right});
      }
    }
    sort(psar.begin(), psar.end());
    int kk = 0;
    for (int j = 0; j < psar.size(); j++) {
      psar[j].first = max(kk, psar[j].first);
      scan[psar[j].first]++;
      scan[psar[j].second + 1]--;
      kk = psar[j].second + 1;
    }
    int res = 0;
    if (i == n - 1) {
      for (int i = 1; i <= m; i++) {
        res += scan[i];
        cout << res << " ";
      }
      cout << endl;
    }
  }
}


Fixed submission:
#include <algorithm>
#include <bitset>
#include <cmath>
#include <complex>
#include <deque>
#include <fstream>
#include <iostream>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <time.h>
#include <vector>

using std::cerr;
using std::cin;
using std::cout;
using std::endl;

using std::bitset;
using std::complex;
using std::deque;
using std::iterator;
using std::map;
using std::multimap;
using std::multiset;
using std::pair;
using std::queue;
using std::set;
using std::stack;
using std::string;
using std::vector;

using std::fill;
using std::ios_base;
using std::max_element;
using std::min_element;
using std::reverse;
using std::sort;
using std::stable_sort;
using std::swap;
using std::unique;

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<long long> vl;
typedef string S;
typedef complex<double> cd;

inline ll max(ll a, ll b) {
  if (a > b)
    return a;
  return b;
}

inline ll min(ll a, ll b) {
  if (a < b)
    return a;
  return b;
}

namespace MySpace {
struct Small_Segment_Tree {
  vector<int> a;
  int l, r;

private:
  int __summ(int L, int R, int l, int r, int v) {
    if (L <= l && r <= R)
      return a[v];
    if (R <= l || r <= L)
      return 0;
    int m = (l + r) / 2;
    return __summ(L, R, l, m, 2 * v + 1) + __summ(L, R, m, r, 2 * v + 2);
  }

  void __set(int P, int l, int r, int v, int V) {
    if (l + 1 == r) {
      a[v] = V;
      return;
    }
    int m = (l + r) / 2;
    if (P < m) {
      __set(P, l, m, 2 * v + 1, V);
      a[v] = a[2 * v + 1] + a[2 * v + 2];
    } else {
      __set(P, m, r, 2 * v + 2, V);
      a[v] = a[2 * v + 1] + a[2 * v + 2];
    }
  }

public:
  int Summ(int L, int R) {
    if (R < L)
      return 0;
    return __summ(L, R + 1, l, r, 0);
  }

  void Set(int P, int V) { __set(P, l, r, 0, V); }

  Small_Segment_Tree(int _n) {
    a.resize(4 * _n);
    l = 0, r = _n;
  }
};
long long inq(long long x, long long q, long long MOD) {
  if (q == 0)
    return 1;
  long long l = inq(x, q / 2, MOD);
  if (q % 2)
    return l * l % MOD * x % MOD;
  return l * l % MOD;
}
}; // namespace MySpace

using namespace MySpace;

#define F(i, n) for (int(i) = 0; (i) != (n); (i)++)
#define fi first
#define se second
#define re return
#define all(x) (x).begin(), (x).end()

const ll MOD = 1e9 + 7;
const ll K = 320;

ll n, m;
ll scan[500000];

int main() {
  ios_base::sync_with_stdio();
  cin.tie(0);
  cout.tie(0);
  cin >> n >> m;
  for (int i = 0; i < n; i++) {
    int l, r;
    cin >> l >> r;
    l--;
    vector<pair<int, int>> psar;
    for (int j = 1; j <= K; j++) {
      if (r / j != l / j) {
        // cout << l << " " << r << " : " << l / j << " " << r / j << " " << j
        // << endl;
        scan[j]++;
        scan[j + 1]--;
        int left = l / j + 1;
        int right = r / j;
        left = max(left, K + 1);
        if (right < K + 1)
          continue;
        psar.push_back({left, right});
      }
    }
    reverse(psar.begin(), psar.end());
    int kk = 0;
    for (int j = 0; j < psar.size(); j++) {
      psar[j].first = max(kk, psar[j].first);
      scan[psar[j].first]++;
      scan[psar[j].second + 1]--;
      kk = psar[j].second + 1;
    }
    int res = 0;
    if (i == n - 1) {
      for (int i = 1; i <= m; i++) {
        res += scan[i];
        cout << res << " ";
      }
      cout << endl;
    }
  }
}