Problem p02869 (C++)

Buggy submission (status: Runtime Error):
#include <bits/stdc++.h>
using namespace std;
#define rep(i, N) for (int i = 0, i##_max = (N); i < i##_max; ++i)
#define repp(i, l, r) for (int i = (l), i##_max = (r); i < i##_max; ++i)
#define per(i, N) for (int i = (N)-1; i >= 0; --i)
#define perr(i, l, r) for (int i = r - 1, i##_min(l); i >= i##_min; --i)
#define all(arr) (arr).begin(), (arr).end()
#define SP << " " <<
#define SPF << " "
#define SPEEDUP                                                                \
  cin.tie(0);                                                                  \
  ios::sync_with_stdio(false);
#define MAX_I INT_MAX      // 1e9
#define MIN_I INT_MIN      //-1e9
#define MAX_UI UINT_MAX    // 1e9
#define MAX_LL LLONG_MAX   // 1e18
#define MIN_LL LLONG_MIN   //-1e18
#define MAX_ULL ULLONG_MAX // 1e19
typedef long long ll;
typedef pair<int, int> PII;
typedef pair<char, char> PCC;
typedef pair<ll, ll> PLL;
typedef pair<char, int> PCI;
typedef pair<int, char> PIC;
typedef pair<ll, int> PLI;
typedef pair<int, ll> PIL;
typedef pair<ll, char> PLC;
typedef pair<char, ll> PCL;

inline void YesNo(bool b) { cout << (b ? "Yes" : "No") << endl; }
inline void YESNO(bool b) { cout << (b ? "YES" : "NO") << endl; }
inline void Yay(bool b) { cout << (b ? "Yay!" : ":(") << endl; }

struct tri {
  ll f, s, t;
};

bool comp(const tri &l, const tri &r) { return l.t < r.t; }

int main(void) {
  SPEEDUP
  cout << setprecision(15);
  int N;
  ll K;
  cin >> N >> K;
  vector<tri> v(N);
  ll b;
  b = K + 2 * N - 1;
  int index = 0;
  repp(x, K, K + N) {
    if (x & 1 == 0)
      continue;
    v[index].f = x;
    v[index].s = b;
    v[index].t = x + b;
    ++index;
    --b;
  }
  repp(x, K, K + N) {
    if (x & 1)
      continue;
    v[index].f = x;
    v[index].s = b;
    v[index].t = x + b;
    ++index;
    --b;
  }

  sort(all(v), comp);
  ll c = K + 2 * N;
  rep(i, N) {
    if (v[i].t > c) {
      cout << -1 << endl;
      return 0;
    }
    v[i].t = c;
    ++c;
  }
  rep(i, N) cout << v[i].f SP v[i].s SP v[i].t << endl;
  return 0;
}


Fixed submission:
#include <bits/stdc++.h>
using namespace std;
#define rep(i, N) for (int i = 0, i##_max = (N); i < i##_max; ++i)
#define repp(i, l, r) for (int i = (l), i##_max = (r); i < i##_max; ++i)
#define per(i, N) for (int i = (N)-1; i >= 0; --i)
#define perr(i, l, r) for (int i = r - 1, i##_min(l); i >= i##_min; --i)
#define all(arr) (arr).begin(), (arr).end()
#define SP << " " <<
#define SPF << " "
#define SPEEDUP                                                                \
  cin.tie(0);                                                                  \
  ios::sync_with_stdio(false);
#define MAX_I INT_MAX      // 1e9
#define MIN_I INT_MIN      //-1e9
#define MAX_UI UINT_MAX    // 1e9
#define MAX_LL LLONG_MAX   // 1e18
#define MIN_LL LLONG_MIN   //-1e18
#define MAX_ULL ULLONG_MAX // 1e19
typedef long long ll;
typedef pair<int, int> PII;
typedef pair<char, char> PCC;
typedef pair<ll, ll> PLL;
typedef pair<char, int> PCI;
typedef pair<int, char> PIC;
typedef pair<ll, int> PLI;
typedef pair<int, ll> PIL;
typedef pair<ll, char> PLC;
typedef pair<char, ll> PCL;

inline void YesNo(bool b) { cout << (b ? "Yes" : "No") << endl; }
inline void YESNO(bool b) { cout << (b ? "YES" : "NO") << endl; }
inline void Yay(bool b) { cout << (b ? "Yay!" : ":(") << endl; }

struct tri {
  ll f, s, t;
};

bool comp(const tri &l, const tri &r) { return l.t < r.t; }

int main(void) {
  SPEEDUP
  cout << setprecision(15);
  int N;
  ll K;
  cin >> N >> K;
  vector<tri> v(N);
  ll b;
  b = K + 2 * N - 1;
  int index = 0;
  repp(x, K, K + N) {
    if ((x & 1) == 0)
      continue;
    v[index].f = x;
    v[index].s = b;
    v[index].t = x + b;
    ++index;
    --b;
  }
  repp(x, K, K + N) {
    if (x & 1)
      continue;
    v[index].f = x;
    v[index].s = b;
    v[index].t = x + b;
    ++index;
    --b;
  }

  sort(all(v), comp);
  ll c = K + 2 * N;
  rep(i, N) {
    if (v[i].t > c) {
      cout << -1 << endl;
      return 0;
    }
    v[i].t = c;
    ++c;
  }
  rep(i, N) cout << v[i].f SP v[i].s SP v[i].t << endl;
  return 0;
}