Problem p02588 (C++) — buggy submission, verdict: Runtime Error

#include <algorithm>
#include <bitset>
#include <cassert>
#include <cmath>
#include <cstdint>
#include <cstdlib>
#include <functional>
#include <iomanip>
#include <iostream>
#include <limits>
#include <map>
#include <math.h>
#include <numeric>
#include <queue>
#include <set>
#include <stack>
#include <string.h>
#include <string>
#include <utility>
#include <vector>

using namespace std;

/* template */

using ll = long long;

void debug_out() { std::cout << std::endl; }

template <typename Head, typename... Tail> void debug_out(Head H, Tail... T) {
  cout << H << " ";
  debug_out(T...);
}

#ifdef LOCAL
#define debug(...)                                                             \\
  cout << "debug: ";                                                           \\
  debug_out(__VA_ARGS__)
#else
#define debug(...)
#endif

#define rep(i, a, n) for (int i = (int)(a); i < (int)(n); i++)
#define rrep(i, a, n) for (int i = ((int)(n - 1)); i >= (int)(a); i--)
#define Rep(i, a, n) for (long long i = (long long)(a); i < (long long)(n); i++)
#define RRep(i, a, n)                                                          \\
  for (long long i = ((long long)(n - 1ll)); i >= (long long)(a); i--)
#define all(v) (v).begin(), (v).end()
#define rall(v) (v).rbegin(), (v).rend()

template <typename T>
std::ostream &operator<<(std::ostream &os, std::vector<T> vec) {
  for (std::size_t i = 0; i < vec.size(); i++)
    os << vec[i] << (i + 1 == vec.size() ? "" : " ");
  return os;
}

struct Edge {
  int to;
  ll weight;
  Edge(int t, ll w) : to(t), weight(w) {}
};

struct edge {
  int from;
  int to;
  ll weight;
  edge(int f, int t, ll w) : from(f), to(t), weight(w) {}
};

using Graph = vector<vector<Edge>>;
using graph = vector<vector<int>>;
using edges = vector<edge>;

template <class T> inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}

template <class T> inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}

template <class T> T lcm(T a, T b) { return (a * b) / gcd(a, b); }

ll ctoi(char c) {
  switch (c) {
  case '0':
    return 0;
  case '1':
    return 1;
  case '2':
    return 2;
  case '3':
    return 3;
  case '4':
    return 4;
  case '5':
    return 5;
  case '6':
    return 6;
  case '7':
    return 7;
  case '8':
    return 8;
  case '9':
    return 9;
  default:
    return 0;
  }
}

constexpr ll LNF = 1LL << 50;

constexpr int INF = 1e9 + 7;

const long double PI = 3.14159265358979323846;

vector<int> dx = {1, 0, -1, 1, -1, 0};
vector<int> dy = {1, 1, 1, 0, 0, -1};

/* template */

constexpr ll ten9 = 1000000000ll;

int main() {
  cin.tie(nullptr);
  ios::sync_with_stdio(false);
  ll n;
  cin >> n;
  double a;
  ll b;
  vector<vector<ll>> p(50, vector<ll>(50, 0));
  ll ans = 0;
  rep(i, 0, n) {
    cin >> a;
    b = (ll)(a * ten9 + 0.3);
    int x = 0, y = 0;
    while (b % 2ll == 0) {
      x++;
      b /= 2ll;
    }
    while (b % 5ll == 0) {
      y++;
      b /= 5ll;
    }
    p[x][y]++;
  }
  rep(i, 0, 50) {
    rep(j, 0, 50) {
      rep(ii, 0, 50) {
        rep(jj, 0, 50) {
          if (pair<int, int>(i, j) <= pair<int, int>(ii, jj)) {
            if (i + ii >= 18 && j + jj >= 18) {
              if (i == ii && j == jj) {
                ans += p[i][j] * (p[i][j] - 1ll) / 2ll;
              } else {
                ans += p[i][j] * p[ii][jj];
              }
            }
          }
        }
      }
    }
  }
  cout << ans << endl;
}

Error: 0

Fixed submission:

#include <algorithm>
#include <bitset>
#include <cassert>
#include <cmath>
#include <cstdint>
#include <cstdlib>
#include <functional>
#include <iomanip>
#include <iostream>
#include <limits>
#include <map>
#include <math.h>
#include <numeric>
#include <queue>
#include <set>
#include <stack>
#include <string.h>
#include <string>
#include <utility>
#include <vector>

using namespace std;

/* template */

using ll = long long;

void debug_out() { std::cout << std::endl; }

template <typename Head, typename... Tail> void debug_out(Head H, Tail... T) {
  cout << H << " ";
  debug_out(T...);
}

#ifdef LOCAL
#define debug(...)                                                             \\
  cout << "debug: ";                                                           \\
  debug_out(__VA_ARGS__)
#else
#define debug(...)
#endif

#define rep(i, a, n) for (int i = (int)(a); i < (int)(n); i++)
#define rrep(i, a, n) for (int i = ((int)(n - 1)); i >= (int)(a); i--)
#define Rep(i, a, n) for (long long i = (long long)(a); i < (long long)(n); i++)
#define RRep(i, a, n)                                                          \\
  for (long long i = ((long long)(n - 1ll)); i >= (long long)(a); i--)
#define all(v) (v).begin(), (v).end()
#define rall(v) (v).rbegin(), (v).rend()

template <typename T>
std::ostream &operator<<(std::ostream &os, std::vector<T> vec) {
  for (std::size_t i = 0; i < vec.size(); i++)
    os << vec[i] << (i + 1 == vec.size() ? "" : " ");
  return os;
}

struct Edge {
  int to;
  ll weight;
  Edge(int t, ll w) : to(t), weight(w) {}
};

struct edge {
  int from;
  int to;
  ll weight;
  edge(int f, int t, ll w) : from(f), to(t), weight(w) {}
};

using Graph = vector<vector<Edge>>;
using graph = vector<vector<int>>;
using edges = vector<edge>;

template <class T> inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}

template <class T> inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}

template <class T> T lcm(T a, T b) { return (a * b) / gcd(a, b); }

ll ctoi(char c) {
  switch (c) {
  case '0':
    return 0;
  case '1':
    return 1;
  case '2':
    return 2;
  case '3':
    return 3;
  case '4':
    return 4;
  case '5':
    return 5;
  case '6':
    return 6;
  case '7':
    return 7;
  case '8':
    return 8;
  case '9':
    return 9;
  default:
    return 0;
  }
}

constexpr ll LNF = 1LL << 50;

constexpr int INF = 1e9 + 7;

const long double PI = 3.14159265358979323846;

vector<int> dx = {1, 0, -1, 1, -1, 0};
vector<int> dy = {1, 1, 1, 0, 0, -1};

/* template */

int main() {
  cin.tie(nullptr);
  ios::sync_with_stdio(false);
  ll n;
  cin >> n;
  vector<string> a(n);
  rep(i, 0, n) cin >> a[i];
  ll m = 20;
  vector<vector<vector<ll>>> tmp(m, vector<vector<ll>>(m, vector<ll>(m, 0)));
  ll ans = 0ll;
  rep(i, 0, n) {
    ll zero = 0;
    ll c = 0;
    int flag = 0;
    int e = a[i].size();
    ll f = 1;
    ll d = 1;
    rep(j, 0, e) {
      if (a[i][j] == '.') {
        flag = 1;
        break;
      }
    }
    rrep(j, 0, e) {
      if (a[i][j] == '.') {
        zero = e - j - d;
        flag = 0;
      } else if (flag > 0 && a[i][j] == '0') {
        flag++;
        d++;
        continue;
      } else {
        flag = 0;
        c += (ll)ctoi(a[i][j]) * f;
        f *= 10ll;
      }
    }
    /* ここまでok*/
    pair<ll, ll> p = {0, 0};
    while (c % 2ll == 0ll) {
      p.first++;
      c /= 2ll;
    }
    while (c % 5ll == 0ll) {
      p.second++;
      c /= 5ll;
    }
    ll q = min(p.first, p.second);
    p.first -= q;
    p.second -= q;
    q -= zero;
    rep(j, 0, 20) {
      rep(k, 0, 20) {
        int r = min(j + p.first, k + p.second);
        if (q + r < 0)
          continue;
        rep(l, 0, min(q + r, m - 1) + 1) { ans += tmp[j][k][l]; }
      }
    }
    tmp[p.first][p.second][zero]++;
  }
  cout << ans << endl;
}