Problem p02962 (C++)

Buggy submission (status: Runtime Error):
#include <algorithm>
#include <bitset>
#include <ciso646>
#include <cmath>
#include <complex>
#include <cstdio>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <tuple>
#include <unordered_map>
#include <utility>
#include <vector>
using namespace std;
typedef long long ll;
typedef unsigned int ui;
const ll mod = 1000000007;
const ll INF = (ll)1000000007 * 1000000007;
typedef pair<int, int> P;
#define stop                                                                   \
  char nyaa;                                                                   \
  cin >> nyaa;
#define rep(i, n) for (int i = 0; i < n; i++)
#define per(i, n) for (int i = n - 1; i >= 0; i--)
#define Rep(i, sta, n) for (int i = sta; i < n; i++)
#define Per(i, sta, n) for (int i = n - 1; i >= sta; i--)
#define rep1(i, n) for (int i = 1; i <= n; i++)
#define per1(i, n) for (int i = n; i >= 1; i--)
#define Rep1(i, sta, n) for (int i = sta; i <= n; i++)
typedef long double ld;
typedef complex<ld> Point;
const ld eps = 1e-8;
const ld pi = acos(-1.0);
typedef pair<ll, ll> LP;

int gcd(int a, int b) {
  if (a < b)
    swap(a, b);
  if (b == 0)
    return a;
  return gcd(b, a % b);
}

// kmp をやるための前計算
vector<int> makeTable(const string &s) {
  int n = s.size();
  vector<int> ret(n + 1);
  ret[0] = -1;
  int j = -1;
  for (int i = 0; i < n; i++) {
    while (j >= 0 && s[i] != s[j])
      j = ret[j];
    ret[i + 1] = ++j;
  }
  return ret;
}

// str の中に word とマッチする場所のリストを返す
// ret のそれぞれの要素 el は, 「str[el] からの文字列が word
// と一致する」ことを示す
vector<int> kmp(const string &str, const string &word) {
  vector<int> table = makeTable(word), ret;
  int m = 0, i = 0, n = str.size();
  while (m + i < n) {
    if (word[i] == str[m + i]) {
      if (++i == (int)(word.size())) {
        ret.push_back(m);
        m = m + i - table[i];
        i = table[i];
      }
    } else {
      m = m + i - table[i];
      if (i > 0)
        i = table[i];
    }
  }
  return ret;
}

string s, s_, t;
int d[1500010];

void solve() {
  cin >> s_ >> t;
  while (s.length() < t.length()) {
    s += s_;
  }
  s += s + s;
  // cout << s << " " << t << endl;
  vector<int> v_ = kmp(s, t), v;
  if (v_.empty()) {
    cout << 0 << endl;
    return;
  }
  int n = 2 * s.length() / 3, sta = v_[0];
  for (int p : v_) {
    if (p - sta >= n)
      break;
    v.push_back(p - sta);
  }
  int g = gcd(n, t.length());
  bool eta = true;
  int ans = 0;
  for (int p : v) {
    // cout << p << endl;
    if (p < t.length())
      d[p] = 1;
    else
      d[p] = d[p - t.length()] + 1;
    ans = max(ans, d[p]);
  }
  rep(i, n / g) {
    if (d[i * g] == 0)
      eta = false;
  }
  if (eta) {
    cout << -1 << endl;
    return;
  } else {
    cout << ans << endl;
  }
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout << fixed << setprecision(50);
  solve();
}

Fixed submission:
#include <algorithm>
#include <bitset>
#include <ciso646>
#include <cmath>
#include <complex>
#include <cstdio>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <tuple>
#include <unordered_map>
#include <utility>
#include <vector>
using namespace std;
typedef long long ll;
typedef unsigned int ui;
const ll mod = 1000000007;
const ll INF = (ll)1000000007 * 1000000007;
typedef pair<int, int> P;
#define stop                                                                   \
  char nyaa;                                                                   \
  cin >> nyaa;
#define rep(i, n) for (int i = 0; i < n; i++)
#define per(i, n) for (int i = n - 1; i >= 0; i--)
#define Rep(i, sta, n) for (int i = sta; i < n; i++)
#define Per(i, sta, n) for (int i = n - 1; i >= sta; i--)
#define rep1(i, n) for (int i = 1; i <= n; i++)
#define per1(i, n) for (int i = n; i >= 1; i--)
#define Rep1(i, sta, n) for (int i = sta; i <= n; i++)
typedef long double ld;
typedef complex<ld> Point;
const ld eps = 1e-8;
const ld pi = acos(-1.0);
typedef pair<ll, ll> LP;

int gcd(int a, int b) {
  if (a < b)
    swap(a, b);
  if (b == 0)
    return a;
  return gcd(b, a % b);
}

// kmp をやるための前計算
vector<int> makeTable(const string &s) {
  int n = s.size();
  vector<int> ret(n + 1);
  ret[0] = -1;
  int j = -1;
  for (int i = 0; i < n; i++) {
    while (j >= 0 && s[i] != s[j])
      j = ret[j];
    ret[i + 1] = ++j;
  }
  return ret;
}

// str の中に word とマッチする場所のリストを返す
// ret のそれぞれの要素 el は, 「str[el] からの文字列が word
// と一致する」ことを示す
vector<int> kmp(const string &str, const string &word) {
  vector<int> table = makeTable(word), ret;
  int m = 0, i = 0, n = str.size();
  while (m + i < n) {
    if (word[i] == str[m + i]) {
      if (++i == (int)(word.size())) {
        ret.push_back(m);
        m = m + i - table[i];
        i = table[i];
      }
    } else {
      m = m + i - table[i];
      if (i > 0)
        i = table[i];
    }
  }
  return ret;
}

string s, s_, t;
int d[3000010];

void solve() {
  cin >> s_ >> t;
  while (s.length() < t.length()) {
    s += s_;
  }
  s += s + s;
  // cout << s << " " << t << endl;
  vector<int> v_ = kmp(s, t), v;
  if (v_.empty()) {
    cout << 0 << endl;
    return;
  }
  int n = 2 * s.length() / 3, sta = v_[0];
  for (int p : v_) {
    if (p - sta >= n)
      break;
    v.push_back(p - sta);
  }
  int g = gcd(n, t.length());
  bool eta = true;
  int ans = 0;
  for (int p : v) {
    // cout << p << endl;
    if (p < t.length())
      d[p] = 1;
    else
      d[p] = d[p - t.length()] + 1;
    ans = max(ans, d[p]);
  }
  rep(i, n / g) {
    if (d[i * g] == 0)
      eta = false;
  }
  if (eta) {
    cout << -1 << endl;
    return;
  } else {
    cout << ans << endl;
  }
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout << fixed << setprecision(50);
  solve();
}