Problem p03364 (C++)

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

// #define int long long
#define reps(i, s, n) for (int(i) = (s); (i) < (n); ++(i))
#define rep(i, n) reps(i, 0, n)
#define rept(i, n) rep(i, (n) + 1)
#define repst(i, s, n) reps(i, s, (n) + 1)
#define reprt(i, n, t) for (int(i) = (n); (i) >= (t); --(i))
#define repr(i, n) reprt(i, n, 0)
#define each(itr, v) for (auto &(itr) : (v))
#define all(c) (c).begin(), (c).end()
#define rall(c) (c).rbegin(), (c).rend()
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define tmax(x, y, z) max(x, max(y, z))
#define tmin(x, y, z) min(x, min(y, z))
#define chmin(x, y) x = min(x, y)
#define chmax(x, y) x = max(x, y)
#define ln '\n'
#define bln(i, n) (((i) == (n)-1) ? '\n' : ' ')
#define dbg(x) cout << #x " = " << (x) << ln << flush
#define dbga(x, n)                                                             \
  {                                                                            \
    cout << #x " : ";                                                          \
    for (int(i) = 0; i < (n); ++i) {                                           \
      cout << ((x)[i]) << (i == ((n)-1) ? '\n' : ' ') << flush;                \
    }                                                                          \
  }
#define zero(a) memset(a, 0, sizeof(a))
#define unq(a) sort(all(a)), a.erase(unique(all(a)), a.end())

typedef long double ld;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<string> vst;
typedef vector<bool> vb;
typedef vector<ld> vld;
typedef vector<pii> vpii;
typedef vector<pll> vpll;
typedef vector<vector<int>> mat;

const ll inf = (ll)1e9 + 10;
const ll linf = (ll)1e18 + 10;
const ll mod = (ll)(1e9 + 7);
const int dx[] = {0, 1, 0, -1};
const int dy[] = {1, 0, -1, 0};
const int ddx[] = {0, 1, 1, 1, 0, -1, -1, -1};
const int ddy[] = {1, 1, 0, -1, -1, -1, 0, 1};
const double eps = 1e-10;

ll mop(ll a, ll b) {
  ll res = 1;
  a %= mod;
  assert(b >= 0);
  for (; b; b >>= 1) {
    if (b & 1)
      res = res * a % mod;
    a = a * a % mod;
  }
  return res;
}
ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a; }
ll lcm(ll a, ll b) { return a * b / gcd(a, b); }

struct oreno_initializer {
  oreno_initializer() {
    cin.tie(0);
    ios::sync_with_stdio(0);
  }
} oreno_initializer;

// ━━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…
// .｡.:( ^ω^)・ﾟ＋.｡.:( ^ω^)・ﾟ＋.｡.:( ^ω^)・ﾟ＋.｡.:( ^ω^)・ﾟ＋.｡.:( ^ω^)・ﾟ＋
// ・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・

int n, res;
string s[300];

signed main() {
  cin >> n;
  rep(i, n) cin >> s[i];
  rep(a, n) {
    string t[300] = {};
    rep(i, n) rep(j, n) t[i][j] = s[(i + a) % n][j % n];
    bool k = 1;
    rep(i, n) rep(j, n) if (t[i][j] != t[j][i]) k = 0;
    if (k)
      res += n;
  }
  cout << res << ln;
}

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

// #define int long long
#define reps(i, s, n) for (int(i) = (s); (i) < (n); ++(i))
#define rep(i, n) reps(i, 0, n)
#define rept(i, n) rep(i, (n) + 1)
#define repst(i, s, n) reps(i, s, (n) + 1)
#define reprt(i, n, t) for (int(i) = (n); (i) >= (t); --(i))
#define repr(i, n) reprt(i, n, 0)
#define each(itr, v) for (auto &(itr) : (v))
#define all(c) (c).begin(), (c).end()
#define rall(c) (c).rbegin(), (c).rend()
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define tmax(x, y, z) max(x, max(y, z))
#define tmin(x, y, z) min(x, min(y, z))
#define chmin(x, y) x = min(x, y)
#define chmax(x, y) x = max(x, y)
#define ln '\n'
#define bln(i, n) (((i) == (n)-1) ? '\n' : ' ')
#define dbg(x) cout << #x " = " << (x) << ln << flush
#define dbga(x, n)                                                             \
  {                                                                            \
    cout << #x " : ";                                                          \
    for (int(i) = 0; i < (n); ++i) {                                           \
      cout << ((x)[i]) << (i == ((n)-1) ? '\n' : ' ') << flush;                \
    }                                                                          \
  }
#define zero(a) memset(a, 0, sizeof(a))
#define unq(a) sort(all(a)), a.erase(unique(all(a)), a.end())

typedef long double ld;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<string> vst;
typedef vector<bool> vb;
typedef vector<ld> vld;
typedef vector<pii> vpii;
typedef vector<pll> vpll;
typedef vector<vector<int>> mat;

const ll inf = (ll)1e9 + 10;
const ll linf = (ll)1e18 + 10;
const ll mod = (ll)(1e9 + 7);
const int dx[] = {0, 1, 0, -1};
const int dy[] = {1, 0, -1, 0};
const int ddx[] = {0, 1, 1, 1, 0, -1, -1, -1};
const int ddy[] = {1, 1, 0, -1, -1, -1, 0, 1};
const double eps = 1e-10;

ll mop(ll a, ll b) {
  ll res = 1;
  a %= mod;
  assert(b >= 0);
  for (; b; b >>= 1) {
    if (b & 1)
      res = res * a % mod;
    a = a * a % mod;
  }
  return res;
}
ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a; }
ll lcm(ll a, ll b) { return a * b / gcd(a, b); }

struct oreno_initializer {
  oreno_initializer() {
    cin.tie(0);
    ios::sync_with_stdio(0);
  }
} oreno_initializer;

// ━━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…
// .｡.:( ^ω^)・ﾟ＋.｡.:( ^ω^)・ﾟ＋.｡.:( ^ω^)・ﾟ＋.｡.:( ^ω^)・ﾟ＋.｡.:( ^ω^)・ﾟ＋
// ・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・‥…━━━☆・

int n, res;
string s[300];

signed main() {
  cin >> n;
  rep(i, n) cin >> s[i];
  rep(a, n) {
    string t[300] = {};
    rep(i, n) rep(j, n) t[i].pb(s[(i + a) % n][j % n]);
    bool k = 1;
    rep(i, n) rep(j, n) if (t[i][j] != t[j][i]) k = 0;
    if (k)
      res += n;
  }
  cout << res << ln;
}