Problem p02574 (C++) — buggy submission, verdict: Runtime Error

// Never stop trying
#pragma GCC target("avx2")
#pragma GCC optimization("O3")
#pragma GCC optimization("unroll-loops")
#include <bits/stdc++.h>
using namespace std;
#define boost                                                                  \\
  ios_base::sync_with_stdio(false);                                            \\
  cin.tie(0);                                                                  \\
  cout.tie(0)

typedef string str;
typedef long long ll;
#define int ll
typedef double db;
typedef long double ld;
typedef pair<int, int> pi;
#define fi first
#define se second
typedef vector<int> vi;
typedef vector<pi> vpi;
typedef vector<str> vs;
typedef vector<ld> vd;
#define pb push_back
#define sz(x) (int)x.size()
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
#define endl "\\n"

#define FOR(i, a, b) for (int i = (a); i < (b); ++i)
#define F0R(i, a) FOR(i, 0, a)
#define ROF(i, a, b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i, a) ROF(i, 0, a)

const int MOD = 1e9 + 7; // 998244353
const ll INF = 1e18;
const int MX = 1e6 + 10;
const int nx[4] = {0, 0, 1, -1}, ny[4] = {1, -1, 0, 0}; // right left down up

template <class T> using V = vector<T>;
template <class T> bool ckmin(T &a, const T &b) { return a > b ? a = b, 1 : 0; }
template <class T> bool ckmax(T &a, const T &b) { return a < b ? a = b, 1 : 0; }

ll cdiv(ll a, ll b) {
  return a / b + ((a ^ b) > 0 && a % b);
} // divide a by b rounded up
constexpr int log2(int x) { return 31 - __builtin_clz(x); } // floor(log2(x))

#define dbg(x) cerr << " - " << #x << " : " << x << endl;
#define dbgs(x, y)                                                             \\
  cerr << " - " << #x << " : " << x << " / " << #y << " : " << y << endl;
#define dbgv(v)                                                                \\
  cerr << " - " << #v << " : " << endl << "[ ";                                \\
  for (auto it : v)                                                            \\
    cerr << it << ' ';                                                         \\
  cerr << ']' << endl;

void IO() {
#ifndef ONLINE_JUDGE
  freopen("input.txt", "r", stdin);
  freopen("output.txt", "w", stdout);
#endif
}

int N;
vi a(MX);
vi vec;
bool vis[MX];
int spf[MX];

void f(int x) {
  while (x > 1) {
    vec.pb(spf[x]);
    int b = spf[x];
    while (x % b == 0)
      x /= b;
  }
}

void sieve() {
  for (int i = 2; i < 1000001; i++)
    if (spf[i] == -1) {
      for (int j = i; j < 1000001; j += i)
        spf[j] = i;
    }
}

int32_t main() {
  boost;
  IO();
  FOR(i, 0, MX) spf[i] = -1;
  FOR(i, 0, MX) vis[i] = false;

  sieve();
  cin >> N;
  for (int i = 0; i < N; i++)
    cin >> a[i];

  int GCD = a[0];
  FOR(i, 1, N) GCD = __gcd(GCD, a[i]);

  bool sw = true;
  for (int i = N - 1; i >= 0 && sw; i--) {
    vec.clear();
    f(a[i]);
    bool y = false;
    for (auto x : vec)
      if (vis[x])
        y = true;
    if (y)
      sw = false;

    for (auto x : vec)
      vis[x] = true;
  }

  if (sw)
    cout << "pairwise coprime" << endl;
  else if (GCD == 1)
    cout << "setwise coprime" << endl;
  else
    cout << "not coprime" << endl;

  set<int> p;

  return 0;
}

/* Careful!!!
        .Array bounds
        .Infinite loops
        .Uninitialized variables / empty containers
        .Order of input

   Some insights:
        .Binary search
        .Graph representation
        .Write brute force code
        .Change your approach
*/


Error: WA

Fixed submission:

// Never stop trying
#pragma GCC target("avx2")
#pragma GCC optimization("O3")
#pragma GCC optimization("unroll-loops")
#include <bits/stdc++.h>
using namespace std;
#define boost                                                                  \\
  ios_base::sync_with_stdio(false);                                            \\
  cin.tie(0);                                                                  \\
  cout.tie(0)

typedef string str;
typedef long long ll;
#define int ll
typedef double db;
typedef long double ld;
typedef pair<int, int> pi;
#define fi first
#define se second
typedef vector<int> vi;
typedef vector<pi> vpi;
typedef vector<str> vs;
typedef vector<ld> vd;
#define pb push_back
#define sz(x) (int)x.size()
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
#define endl "\\n"

#define FOR(i, a, b) for (int i = (a); i < (b); ++i)
#define F0R(i, a) FOR(i, 0, a)
#define ROF(i, a, b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i, a) ROF(i, 0, a)

const int MOD = 1e9 + 7; // 998244353
const ll INF = 1e18;
const int MX = 2e5 + 10;
const int nx[4] = {0, 0, 1, -1}, ny[4] = {1, -1, 0, 0}; // right left down up

template <class T> using V = vector<T>;
template <class T> bool ckmin(T &a, const T &b) { return a > b ? a = b, 1 : 0; }
template <class T> bool ckmax(T &a, const T &b) { return a < b ? a = b, 1 : 0; }

ll cdiv(ll a, ll b) {
  return a / b + ((a ^ b) > 0 && a % b);
} // divide a by b rounded up
constexpr int log2(int x) { return 31 - __builtin_clz(x); } // floor(log2(x))

#define dbg(x) cerr << " - " << #x << " : " << x << endl;
#define dbgs(x, y)                                                             \\
  cerr << " - " << #x << " : " << x << " / " << #y << " : " << y << endl;
#define dbgv(v)                                                                \\
  cerr << " - " << #v << " : " << endl << "[ ";                                \\
  for (auto it : v)                                                            \\
    cerr << it << ' ';                                                         \\
  cerr << ']' << endl;

void IO() {
#ifndef ONLINE_JUDGE
  freopen("input.txt", "r", stdin);
  freopen("output.txt", "w", stdout);
#endif
}

int N;
vi a(MX);
vi vec;
bool vis[1000001];
int spf[1000001];

void f(int x) {
  while (x > 1) {
    vec.pb(spf[x]);
    int b = spf[x];
    while (x % b == 0)
      x /= b;
  }
}

void sieve() {
  for (int i = 2; i < 1000001; i++)
    if (spf[i] == -1) {
      for (int j = i; j < 1000001; j += i)
        spf[j] = i;
    }
}

int32_t main() {
  boost;
  IO();
  memset(spf, -1, sizeof(spf));
  sieve();
  cin >> N;
  memset(vis, false, sizeof(vis));
  for (int i = 0; i < N; i++)
    cin >> a[i];

  int GCD = a[0];
  FOR(i, 1, N) GCD = __gcd(GCD, a[i]);

  bool sw = true;
  for (int i = N - 1; i >= 0 && sw; i--) {
    vec.clear();
    f(a[i]);
    bool y = false;
    for (auto x : vec)
      if (vis[x])
        y = true;
    if (y)
      sw = false;

    for (auto x : vec)
      vis[x] = true;
  }

  if (sw)
    cout << "pairwise coprime" << endl;
  else if (GCD == 1)
    cout << "setwise coprime" << endl;
  else
    cout << "not coprime" << endl;

  set<int> p;

  return 0;
}

/* Careful!!!
        .Array bounds
        .Infinite loops
        .Uninitialized variables / empty containers
        .Order of input

   Some insights:
        .Binary search
        .Graph representation
        .Write brute force code
        .Change your approach
*/