Problem p02549 (C++) — buggy submission, verdict: Time Limit Exceeded

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define in(a)                                                                  \\
  ll a;                                                                        \\
  cin >> a;
#define in2(a, b)                                                              \\
  ll a, b;                                                                     \\
  cin >> a >> b;
#define in3(a, b, c)                                                           \\
  ll a, b, c;                                                                  \\
  cin >> a >> b >> c;
#define in4(a, b, c, d)                                                        \\
  ll a, b, c, d;                                                               \\
  cin >> a >> b >> c >> d;
#define in5(a, b, c, d, e)                                                     \\
  ll a, b, c, d, e;                                                            \\
  cin >> a >> b >> c >> d >> e;
#define lelo(b)                                                                \\
  for (auto &i : b)                                                            \\
    cin >> i;
#define ff first
#define ss second
#define call(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
#define show(x)                                                                \\
  for (auto t : x)                                                             \\
    cout << t << " ";
#define pb push_back
#define bhar(s, v) memset(s, v, sizeof(s))
#define endl "\\n"
#define ce(x) cout << x << "\\n";
#define nl cout << endl;
#define jaldi                                                                  \\
  ios_base::sync_with_stdio(false);                                            \\
  cin.tie(NULL);
#define dekh_lo ce("dekh_lo");
#define sz(x) (ll) x.size()
#define re return

void __print(int x) { cerr << x; }
void __print(long x) { cerr << x; }
void __print(long long x) { cerr << x; }
void __print(unsigned x) { cerr << x; }
void __print(unsigned long x) { cerr << x; }
void __print(unsigned long long x) { cerr << x; }
void __print(float x) { cerr << x; }
void __print(double x) { cerr << x; }
void __print(long double x) { cerr << x; }
void __print(char x) { cerr << '\\'' << x << '\\''; }
void __print(const char *x) { cerr << '\\"' << x << '\\"'; }
void __print(const string &x) { cerr << '\\"' << x << '\\"'; }
void __print(bool x) { cerr << (x ? "true" : "false"); }

template <typename T, typename V> void __print(const pair<T, V> &x) {
  cerr << '{';
  __print(x.first);
  cerr << ',';
  __print(x.second);
  cerr << '}';
}
template <typename T> void __print(const T &x) {
  int f = 0;
  cerr << '{';
  for (auto &i : x)
    cerr << (f++ ? "," : ""), __print(i);
  cerr << "}";
}
void _print() { cerr << "]\\n"; }
template <typename T, typename... V> void _print(T t, V... v) {
  __print(t);
  if (sizeof...(v))
    cerr << ", ";
  _print(v...);
}
#ifndef ONLINE_JUDGE
#define debug(x...)                                                            \\
  cerr << "[" << #x << "] = [";                                                \\
  _print(x)
#else
#define debug(x...)
#endif

typedef pair<ll, ll> pii;
typedef vector<pii> vii;
typedef vector<ll> vi;

const ll mod = 998244353;
const ll N = 2e5 + 5;

/*


*/

void solve() {
  ll n, k;
  cin >> n >> k;

  vector<ll> l(k);
  vector<ll> r(k);
  for (ll i = 0; i < k; i++)
    cin >> l[i] >> r[i];

  vector<long long> dp(n, 0);
  dp[0] = 1;
  dp[1] = -1;

  for (long long i = 0; i < n; i++) {
    if (i > 0)
      dp[i] += dp[i - 1];
    dp[i] %= mod;
    for (ll j = 0; j < k; j++) {
      if (i + l[j] < n) {
        dp[i + l[j]] += dp[i];
        dp[i + l[j]] %= mod;
      }

      if (i + r[j] + 1 < n) {
        dp[i + r[j] + 1] -= dp[i];
        dp[i + r[j] + 1] += mod;
        dp[i + r[j] + 1] %= mod;
      }
    }
  }

  cout << dp[n - 1] << endl;
}

int32_t main() {
  jaldi ll t;
  // cin>>t;
  t = 1;
  while (t--) {
    solve();
  }
}

/*


*/


Error: TLE

Fixed submission:

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define in(a)                                                                  \\
  ll a;                                                                        \\
  cin >> a;
#define in2(a, b)                                                              \\
  ll a, b;                                                                     \\
  cin >> a >> b;
#define in3(a, b, c)                                                           \\
  ll a, b, c;                                                                  \\
  cin >> a >> b >> c;
#define in4(a, b, c, d)                                                        \\
  ll a, b, c, d;                                                               \\
  cin >> a >> b >> c >> d;
#define in5(a, b, c, d, e)                                                     \\
  ll a, b, c, d, e;                                                            \\
  cin >> a >> b >> c >> d >> e;
#define lelo(b)                                                                \\
  for (auto &i : b)                                                            \\
    cin >> i;
#define ff first
#define ss second
#define call(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
#define show(x)                                                                \\
  for (auto t : x)                                                             \\
    cout << t << " ";
#define pb push_back
#define bhar(s, v) memset(s, v, sizeof(s))
#define endl "\\n"
#define ce(x) cout << x << "\\n";
#define nl cout << endl;
#define jaldi                                                                  \\
  ios_base::sync_with_stdio(false);                                            \\
  cin.tie(NULL);
#define dekh_lo ce("dekh_lo");
#define sz(x) (ll) x.size()
#define re return

void __print(int x) { cerr << x; }
void __print(long x) { cerr << x; }
void __print(long long x) { cerr << x; }
void __print(unsigned x) { cerr << x; }
void __print(unsigned long x) { cerr << x; }
void __print(unsigned long long x) { cerr << x; }
void __print(float x) { cerr << x; }
void __print(double x) { cerr << x; }
void __print(long double x) { cerr << x; }
void __print(char x) { cerr << '\\'' << x << '\\''; }
void __print(const char *x) { cerr << '\\"' << x << '\\"'; }
void __print(const string &x) { cerr << '\\"' << x << '\\"'; }
void __print(bool x) { cerr << (x ? "true" : "false"); }

template <typename T, typename V> void __print(const pair<T, V> &x) {
  cerr << '{';
  __print(x.first);
  cerr << ',';
  __print(x.second);
  cerr << '}';
}
template <typename T> void __print(const T &x) {
  int f = 0;
  cerr << '{';
  for (auto &i : x)
    cerr << (f++ ? "," : ""), __print(i);
  cerr << "}";
}
void _print() { cerr << "]\\n"; }
template <typename T, typename... V> void _print(T t, V... v) {
  __print(t);
  if (sizeof...(v))
    cerr << ", ";
  _print(v...);
}
#ifndef ONLINE_JUDGE
#define debug(x...)                                                            \\
  cerr << "[" << #x << "] = [";                                                \\
  _print(x)
#else
#define debug(x...)
#endif

typedef pair<ll, ll> pii;
typedef vector<pii> vii;
typedef vector<ll> vi;

const ll mod = 1e9 + 7;
const ll N = 2e5 + 5;
ll i, j;

/*


*/
vi dp(N, 0);
void solve() {
  in2(n, k);
  ll ss = k;
  vi s;
  while (ss--) {
    in2(l, r);
    for (i = l; i <= r; i++) {
      s.pb(i);
    }
  }
  // debug(s);
  dp[1] = 1;
  for (i = 2; i <= n; i++) {
    for (auto it : s) {
      ll st = i - it;
      if (st >= 1) {
        dp[i] = (dp[i] + dp[st]) % 998244353;
      }
    }
  }

  ll ans = dp[n] % 998244353;
  ce(ans);
}

int32_t main() {
  // jaldi
  ll t;
  // cin>>t;
  t = 1;
  while (t--) {
    solve();
  }
}

/*


*/