Problem p02549 (C++) — buggy submission, verdict: Runtime Error

/*/ Author: KaySeeKay /*/

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

/*/---------------------------Defines-----------------------------------------/*/

#pragma GCC optimize("Ofast")
#define int long long
#define IOS                                                                    \\
  ios_base::sync_with_stdio(false);                                            \\
  cin.tie(NULL);
#define pb push_back
#define eb emplace_back
#define fn for (int i = 0; i < n; i++)
#define fn1 for (int i = 1; i <= n; i++)
#define fm for (int j = 0; j < m; j++)
#define fm1 for (int j = 1; j <= m; j++)
#define fi first
#define se second
#define endl '\\n'
#define PI 3.14159265358979323846
#define MOD 998244353
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
const int N = 2e6 + 5;
const int INF = 1e18L;
// mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
/*/-----------------------------Debug
 * begins----------------------------------/*/
vector<string> split(const string &s, char c) {
  vector<string> v;
  stringstream ss(s);
  string x;
  while (getline(ss, x, c))
    v.emplace_back(x);
  return move(v);
}
template <typename T, typename... Args> inline string arrStr(T arr, int n) {
  stringstream s;
  s << "[";
  for (int i = 0; i < n - 1; i++)
    s << arr[i] << ",";
  if (n > 0)
    s << arr[n - 1];
  s << "]";
  return s.str();
}
#define trace(args...)                                                         \\
  {                                                                            \\
    __trace_begin(__LINE__);                                                   \\
    __trace(split(#args, ',').begin(), args);                                  \\
  }
inline void __trace_begin(int line) { cerr << "#" << line << ": "; }
template <typename T> inline void __trace_out_var(vector<T> val) {
  cerr << arrStr(val, val.size());
}
template <typename T> inline void __trace_out_var(T *val) {
  cerr << arrStr(val, 10);
}
template <typename T> inline void __trace_out_var(T val) { cerr << val; }
inline void __trace(vector<string>::iterator it) { cerr << endl; }

template <typename T, typename... Args>
inline void __trace(vector<string>::iterator it, T a, Args... args) {
  cerr << it->substr((*it)[0] == ' ', it->length()) << "=";
  __trace_out_var(a);
  cerr << "; ";
  __trace(++it, args...);
}
/*/-----------------------------Code begins----------------------------------/*/
int ar[N];
inline int add(int x, int y, int mod) {
  if (y >= mod)
    y %= mod;
  if (x >= mod)
    x %= mod;
  x += y;
  return (x >= mod ? x - mod : x);
}
inline int sub(int x, int y, int mod) {
  x -= y;
  if (x + mod <= 0) {
    x %= mod;
  }
  return (x < 0 ? x + mod : x);
}
int dp[N];
signed main() {
#ifndef ONLINE_JUDGE
  freopen("input.txt", "r", stdin);
  freopen("output.txt", "w", stdout);
#endif
  IOS;
  int T = 1;
  // cin >> T;
  while (T--) {
    int n, m;
    cin >> n >> m;
    vector<pair<int, int>> v(m);
    fm {
      int x, y;
      cin >> v[j].fi >> v[j].se;
    }
    sort(all(v));
    int ans;
    dp[1] = 1;
    dp[2] = MOD - 1;
    for (int i = 1; i <= n; i++) {
      dp[i + 1] += dp[i];
      dp[i] %= MOD;
      fm {
        int l = v[j].fi;
        int r = v[j].se;
        dp[i + l] += dp[i];
        dp[i + r + 1] -= dp[i];
      }
    }
    ans = dp[n];
    cout << ans;
  }
  return 0;
}


Error: -6
terminate called after throwing an instance of 'std::bad_alloc'
  what():  std::bad_alloc


Fixed submission:

/*/ Author: KaySeeKay /*/

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

/*/---------------------------Defines-----------------------------------------/*/

#pragma GCC optimize("Ofast")
#define int long long
#define IOS                                                                    \\
  ios_base::sync_with_stdio(false);                                            \\
  cin.tie(NULL);
#define pb push_back
#define eb emplace_back
#define fn for (int i = 0; i < n; i++)
#define fn1 for (int i = 1; i <= n; i++)
#define fm for (int j = 0; j < m; j++)
#define fm1 for (int j = 1; j <= m; j++)
#define fi first
#define se second
#define endl '\\n'
#define PI 3.14159265358979323846
#define MOD 998244353
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
const int N = 2e6 + 5;
const int INF = 1e18L;
// mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
/*/-----------------------------Debug
 * begins----------------------------------/*/
vector<string> split(const string &s, char c) {
  vector<string> v;
  stringstream ss(s);
  string x;
  while (getline(ss, x, c))
    v.emplace_back(x);
  return move(v);
}
template <typename T, typename... Args> inline string arrStr(T arr, int n) {
  stringstream s;
  s << "[";
  for (int i = 0; i < n - 1; i++)
    s << arr[i] << ",";
  if (n > 0)
    s << arr[n - 1];
  s << "]";
  return s.str();
}
#define trace(args...)                                                         \\
  {                                                                            \\
    __trace_begin(__LINE__);                                                   \\
    __trace(split(#args, ',').begin(), args);                                  \\
  }
inline void __trace_begin(int line) { cerr << "#" << line << ": "; }
template <typename T> inline void __trace_out_var(vector<T> val) {
  cerr << arrStr(val, val.size());
}
template <typename T> inline void __trace_out_var(T *val) {
  cerr << arrStr(val, 10);
}
template <typename T> inline void __trace_out_var(T val) { cerr << val; }
inline void __trace(vector<string>::iterator it) { cerr << endl; }

template <typename T, typename... Args>
inline void __trace(vector<string>::iterator it, T a, Args... args) {
  cerr << it->substr((*it)[0] == ' ', it->length()) << "=";
  __trace_out_var(a);
  cerr << "; ";
  __trace(++it, args...);
}
/*/-----------------------------Code begins----------------------------------/*/
int ar[N];
inline int add(int x, int y, int mod) {
  if (y >= mod)
    y %= mod;
  if (x >= mod)
    x %= mod;
  x += y;
  return (x >= mod ? x - mod : x);
}
inline int sub(int x, int y, int mod) {
  x -= y;
  if (x + mod <= 0) {
    x %= mod;
  }
  return (x < 0 ? x + mod : x);
}
signed main() {
#ifndef ONLINE_JUDGE
  freopen("input.txt", "r", stdin);
  freopen("output.txt", "w", stdout);
#endif
  IOS;
  int T = 1;
  // cin >> T;
  while (T--) {
    int n, m;
    cin >> n >> m;
    vector<int> dp(2 * n + 1);
    vector<pair<int, int>> v(m);
    fm {
      int x, y;
      cin >> v[j].fi >> v[j].se;
    }
    sort(all(v));
    int ans;
    dp[1] = 1;
    dp[2] = MOD - 1;
    for (int i = 1; i <= n; i++) {
      dp[i + 1] += dp[i];
      dp[i] %= MOD;
      fm {
        int l = v[j].fi;
        int r = v[j].se;
        dp[i + l] += dp[i];
        dp[i + r + 1] -= dp[i];
      }
    }
    ans = dp[n];
    cout << ans;
  }
  return 0;
}