Problem p03952 (C++)

Buggy submission (status: Runtime Error):
#include <bits/stdc++.h>
using namespace std;

using ll = long long;

#define REP(i, n) for (int i = 0; i < n; i++)
#define REPR(i, n) for (int i = n; i >= 0; i--)
#define FOR(i, m, n) for (int i = m; i < n; i++)
#define pb push_back
#define mp make_pair
#define fill(x, y) memset(x, y, sizeof(x))
#define even(x) x % 2 == 0
#define odd(x) x % 2 != 0
#define all(x) x.begin(), x.end()
#define pcnt __builtin_popcount
#define buli(x) __builtin_popcountll(x)
#define F first
#define S second
#define UNIQUE(v) v.erase(unique(v.begin(), v.end()), v.end());

// these functions return the position of result of Binary Search.
#define LB(s, t, x) (int)(lower_bound(s, t, x) - s)
#define UB(s, t, x) (int)(upper_bound(s, t, x) - s)

ll qp(ll a, ll b, int mo) {
  ll ans = 1;
  do {
    if (b & 1)
      ans = 1ll * ans * a % mo;
    a = 1ll * a * a % mo;
  } while (b >>= 1);
  return ans;
}
ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a; }
int dx[4] = {1, 0, -1, 0};
int dy[4] = {0, 1, 0, -1};
int dx8[] = {1, -1, 0, 0, 1, 1, -1, -1};
int dy8[] = {0, 0, -1, 1, -1, 1, -1, 1};

template <typename T> vector<T> make_v(size_t a) { return vector<T>(a); }
template <typename T, typename... Ts>
auto make_v(size_t a, size_t b, Ts... ts) {
  return vector<decltype(make_v<T>(b, ts...))>(a, make_v<T>(b, ts...));
}
template <typename T, typename V>
typename enable_if<is_class<T>::value == 0>::type fill_v(T &t, const V &v) {
  t = v;
}
template <typename T, typename V>
typename enable_if<is_class<T>::value != 0>::type fill_v(T &t, const V &v) {
  for (auto &e : t)
    fill_v(e, v);
}
// auto dp = make_v<int>(4, h, w);
// fill_v(dp, 0);

const ll INF_LL = (1ll << 60);
const int INF_INT = (int)1e9;
const ll MOD_CONST = (ll)(1e9 + 7);

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;
}

inline tuple<ll, ll> rotate45(tuple<ll, ll> p) {
  ll x = get<0>(p), y = get<1>(p);
  return tuple<ll, ll>(x + y, x - y);
}
inline bool rangeCheck2D(int nx, int ny, int Width, int Height) {
  return nx >= 0 and nx < Width and ny >= 0 and ny < Height;
}

int main(void) {
  cin.tie(0);
  ios::sync_with_stdio(0);
  cout << fixed << setprecision(20);

  ll N, X;
  cin >> N >> X;
  ll n2 = 2 * N - 1;
  if (X == 1 or X == n2) {
    cout << "No" << endl;
  } else {
    cout << "Yes" << endl;
    set<ll> cs;
    REP(i, n2) cs.insert(i + 1);
    vector<ll> out(n2);
    out[N - 1] = X;
    cs.erase(X);
    if (X == 2) {
      out[N - 2] = X + 1;
      cs.erase(X + 1);
      out[N] = X - 1;
      cs.erase(X - 1);
      out[N + 1] = X + 2;
      cs.erase(X + 2);
    } else {
      out[N - 2] = X - 1;
      cs.erase(X - 1);
      out[N] = X + 1;
      cs.erase(X + 1);
      out[N + 1] = X - 2;
      cs.erase(X - 2);
    }
    int idx = 0;
    for (auto c : cs) {
      if (idx >= n2)
        continue;
      out[idx] = c;
      idx++;
      if (idx == N - 2) {
        idx = N + 2;
      }
    }
    REP(i, n2) { cout << out[i] << endl; }
  }

  return 0;
}


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

using ll = long long;

#define REP(i, n) for (int i = 0; i < n; i++)
#define REPR(i, n) for (int i = n; i >= 0; i--)
#define FOR(i, m, n) for (int i = m; i < n; i++)
#define pb push_back
#define mp make_pair
#define fill(x, y) memset(x, y, sizeof(x))
#define even(x) x % 2 == 0
#define odd(x) x % 2 != 0
#define all(x) x.begin(), x.end()
#define pcnt __builtin_popcount
#define buli(x) __builtin_popcountll(x)
#define F first
#define S second
#define UNIQUE(v) v.erase(unique(v.begin(), v.end()), v.end());

// these functions return the position of result of Binary Search.
#define LB(s, t, x) (int)(lower_bound(s, t, x) - s)
#define UB(s, t, x) (int)(upper_bound(s, t, x) - s)

ll qp(ll a, ll b, int mo) {
  ll ans = 1;
  do {
    if (b & 1)
      ans = 1ll * ans * a % mo;
    a = 1ll * a * a % mo;
  } while (b >>= 1);
  return ans;
}
ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a; }
int dx[4] = {1, 0, -1, 0};
int dy[4] = {0, 1, 0, -1};
int dx8[] = {1, -1, 0, 0, 1, 1, -1, -1};
int dy8[] = {0, 0, -1, 1, -1, 1, -1, 1};

template <typename T> vector<T> make_v(size_t a) { return vector<T>(a); }
template <typename T, typename... Ts>
auto make_v(size_t a, size_t b, Ts... ts) {
  return vector<decltype(make_v<T>(b, ts...))>(a, make_v<T>(b, ts...));
}
template <typename T, typename V>
typename enable_if<is_class<T>::value == 0>::type fill_v(T &t, const V &v) {
  t = v;
}
template <typename T, typename V>
typename enable_if<is_class<T>::value != 0>::type fill_v(T &t, const V &v) {
  for (auto &e : t)
    fill_v(e, v);
}
// auto dp = make_v<int>(4, h, w);
// fill_v(dp, 0);

const ll INF_LL = (1ll << 60);
const int INF_INT = (int)1e9;
const ll MOD_CONST = (ll)(1e9 + 7);

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;
}

inline tuple<ll, ll> rotate45(tuple<ll, ll> p) {
  ll x = get<0>(p), y = get<1>(p);
  return tuple<ll, ll>(x + y, x - y);
}
inline bool rangeCheck2D(int nx, int ny, int Width, int Height) {
  return nx >= 0 and nx < Width and ny >= 0 and ny < Height;
}

int main(void) {
  cin.tie(0);
  ios::sync_with_stdio(0);
  cout << fixed << setprecision(20);

  ll N, X;
  cin >> N >> X;
  ll n2 = 2 * N - 1;
  if (N == 1) {
    cout << "Yes" << endl;
    cout << 1 << endl;
  } else if (N == 2 and X == 2) {
    cout << "Yes" << endl;
    cout << 1 << endl << 2 << endl << 3 << endl;
  } else if (X == 1 or X == n2) {
    cout << "No" << endl;
  } else {
    cout << "Yes" << endl;
    set<ll> cs;
    REP(i, n2) cs.insert(i + 1);
    vector<ll> out(n2);
    out[N - 1] = X;
    cs.erase(X);
    if (X == 2) {
      out[N - 2] = X + 1;
      cs.erase(X + 1);
      out[N] = X - 1;
      cs.erase(X - 1);
      out[N + 1] = X + 2;
      cs.erase(X + 2);
    } else {
      out[N - 2] = X - 1;
      cs.erase(X - 1);
      out[N] = X + 1;
      cs.erase(X + 1);
      out[N + 1] = X - 2;
      cs.erase(X - 2);
    }
    int idx = 0;
    for (auto c : cs) {
      if (idx >= n2)
        continue;
      out[idx] = c;
      idx++;
      if (idx == N - 2) {
        idx = N + 2;
      }
    }
    REP(i, n2) { cout << out[i] << endl; }
  }

  return 0;
}