Problem p02588 (C++)

Buggy submission (status: Time Limit Exceeded):
// gzhffIThh
#include <bits/stdc++.h>

#define ui unsigned int
#define ll long long
#define ul unsigned ll
#define ld long double

#define pi pair<int, int>
#define fi first
#define se second
#define mp make_pair

#define vi vector<int>
#define pb push_back
#define pq priority_queue

#define sz(x) ((int)x.size())
#define all(x) (x).begin(), (x).end()

#define rep(i, a, b) for (int i = a; i <= b; i++)
#define per(i, a, b) for (int i = b; i >= a; i--)

#define dbg(x) cerr << #x " = " << x << endl
#define debug(...) fprintf(stderr, __VA_ARGS__)

#define fl(x) freopen(x ".in", "r", stdin), freopen(x ".out", "w", stdout);

using namespace std;
namespace io {
const int SI = 1 << 21 | 1;
char IB[SI], *IS, *IT, OB[SI], *OS = OB, *OT = OS + SI - 1, c, ch[100];
int f, t;
#define gc()                                                                   \
  (IS == IT                                                                    \
       ? (IT = (IS = IB) + fread(IB, 1, SI, stdin), IS == IT ? EOF : *IS++)    \
       : *IS++)
inline void flush() { fwrite(OB, 1, OS - OB, stdout), OS = OB; }
inline void pc(char x) {
  *OS++ = x;
  if (OS == OT)
    flush();
}

template <class I> inline void rd(I &x) {
  for (f = 1, c = gc(); c < '0' || c > '9'; c = gc())
    if (c == '-')
      f = -1;
  for (x = 0; c >= '0' && c <= '9';
       x = (x << 3) + (x << 1) + (c & 15), c = gc())
    ;
  x *= f;
}
template <class I> inline void rd(I &x, I &y) { rd(x), rd(y); }
template <class I> inline void rd(I &x, I &y, I &z) { rd(x), rd(y), rd(z); }
template <class I> inline void rda(I *a, int n) {
  for (int i = 1; i <= n; i++)
    rd(a[i]);
}
inline void rdc(char &c) {
  for (c = gc(); c < 33 || c > 126; c = gc())
    ;
}
inline void rds(char *s, int &n) {
  for (c = gc(); c < 33 || c > 126; c = gc())
    ;
  for (n = 0; c >= 33 && c <= 126; s[++n] = c, c = gc())
    ;
  s[n + 1] = '\0';
}
inline void rds(string &s) {
  for (c = gc(); c < 33 || c > 126; c = gc())
    ;
  for (s.clear(); c >= 33 && c <= 126; s.pb(c), c = gc())
    ;
}

template <class I> inline void print(I x, char k = '\n') {
  if (!x)
    pc('0');
  if (x < 0)
    pc('-'), x = -x;
  while (x)
    ch[++t] = x % 10 + '0', x /= 10;
  while (t)
    pc(ch[t--]);
  pc(k);
}
template <class I> inline void print(I x, I y) { print(x, ' '), print(y); }
template <class I> inline void print(I x, I y, I z) {
  print(x, ' '), print(y, ' '), print(z);
}
template <class I> inline void printa(I *a, int n) {
  for (int i = 1; i <= n; i++)
    print(a[i], " \n"[i == n]);
}
inline void printc(char c) { pc(c); }
inline void prints(char *s, int n) {
  for (int i = 1; i <= n; i++)
    pc(s[i]);
  pc('\n');
}
inline void prints(string s) {
  int n = s.length();
  while (t < n)
    pc(s[t++]);
  pc('\n'), t = 0;
}
struct Flush {
  ~Flush() { flush(); }
} flusher;
} // namespace io
using io::print;
using io::printa;
using io::printc;
using io::prints;
using io::rd;
using io::rda;
using io::rdc;
using io::rds;

const int P = 1000000007;

struct modint {
  int x;
  inline modint(int x = 0) : x(x) {}
  inline modint &operator=(int o) { return x = o, *this; }
  inline modint &operator+=(modint o) {
    return x = x + o.x >= P ? x + o.x - P : x + o.x, *this;
  }
  inline modint &operator-=(modint o) {
    return x = x - o.x < 0 ? x - o.x + P : x - o.x, *this;
  }
  inline modint &operator*=(modint o) { return x = 1ll * x * o.x % P, *this; }
  inline modint &operator^=(ll b) {
    modint a = *this, c;
    if (!~b)
      b = P - 2;
    c.x = 1 % P;
    while (b) {
      if (b & 1)
        c *= a;
      a *= a, b >>= 1;
    }
    return x = c.x, *this;
  }
  inline modint &operator/=(modint o) { return *this *= o ^= -1; }
  inline modint &operator+=(int o) {
    return x = x + o >= P ? x + o - P : x + o, *this;
  }
  inline modint &operator-=(int o) {
    return x = x - o < 0 ? x - o + P : x - o, *this;
  }
  inline modint &operator*=(int o) { return x = 1ll * x * o % P, *this; }
  inline modint &operator/=(int o) {
    modint y = modint(o);
    return *this *= y ^= -1;
  }
  template <class I> inline friend modint operator+(modint a, I b) {
    return a += b;
  }
  template <class I> inline friend modint operator-(modint a, I b) {
    return a -= b;
  }
  template <class I> inline friend modint operator*(modint a, I b) {
    return a *= b;
  }
  inline friend modint operator^(modint a, ll b) { return a ^= b; }
  template <class I> inline friend modint operator/(modint a, I b) {
    return a /= b;
  }
  inline friend bool operator==(modint a, int b) { return a.x == b; }
  inline friend bool operator!=(modint a, int b) { return a.x != b; }
  inline friend bool operator<(modint a, int b) { return a.x < b; }
  inline friend bool operator<=(modint a, int b) { return a.x <= b; }
  inline friend bool operator>(modint a, int b) { return a.x > b; }
  inline friend bool operator>=(modint a, int b) { return a.x >= b; }
  inline friend bool operator==(modint a, modint b) { return a.x == b.x; }
  inline friend bool operator!=(modint a, modint b) { return a.x != b.x; }
  inline friend bool operator<(modint a, modint b) { return a.x < b.x; }
  inline friend bool operator<=(modint a, modint b) { return a.x <= b.x; }
  inline friend bool operator>(modint a, modint b) { return a.x > b.x; }
  inline friend bool operator>=(modint a, modint b) { return a.x >= b.x; }
  inline bool operator!() { return !x; }
  inline modint operator-() { return x ? P - x : 0; }
};
inline void rd(modint &x) { rd(x.x); }
inline void print(modint x, char k = '\n') { print(x.x, k); }
template <class T> inline void cmin(T &a, T b) { a = b < a ? b : a; }
template <class T> inline void cmax(T &a, T b) { a = b > a ? b : a; }
// head

const int N = 200010;
const int M = 57;

int n;
long double a[N];
ll g[N], tmp = 1000000000;
int c[M][M];
ll ans;

int main() {

  fl("A");

  rd(n);
  for (int i = 1; i <= n; i++) {
    string s;
    rds(s);
    int p = -1;
    for (ui j = 0; j < s.size(); j++)
      if (s[j] == '.')
        p = j;
    if (!~p)
      p = s.size(), s += ".0";
    while ((int)s.size() - p < 10)
      s += "0";
    ll a = 0;
    for (ui j = 0; j < s.size(); j++)
      if (s[j] != '.')
        a = a * 10 + s[j] - '0';
    int c2 = 0, c5 = 0;
    while (a % 2 == 0)
      ++c2, a /= 2;
    while (a % 5 == 0)
      ++c5, a /= 5;
    c[c2][c5]++;
  }
  for (int i = 0; i < M; i++) {
    for (int j = 0; j < M; j++) {
      for (int k = max(0, 18 - i); k < M; k++) {
        for (int t = max(0, 18 - j); t < M; t++) {
          if (i == k && j == t)
            continue;
          ans += 1ll * c[i][j] * c[k][t];
        }
      }
    }
  }
  for (int i = 9; i < M; i++) {
    for (int j = 9; j < M; j++) {
      if (c[i][j]) {
        ans += 1ll * c[i][j] * (c[i][j] - 1);
      }
    }
  }
  print(ans / 2);

  return 0;
}


Fixed submission:
// gzhffIThh
#include <bits/stdc++.h>

#define ui unsigned int
#define ll long long
#define ul unsigned ll
#define ld long double

#define pi pair<int, int>
#define fi first
#define se second
#define mp make_pair

#define vi vector<int>
#define pb push_back
#define pq priority_queue

#define sz(x) ((int)x.size())
#define all(x) (x).begin(), (x).end()

#define rep(i, a, b) for (int i = a; i <= b; i++)
#define per(i, a, b) for (int i = b; i >= a; i--)

#define dbg(x) cerr << #x " = " << x << endl
#define debug(...) fprintf(stderr, __VA_ARGS__)

#define fl(x) freopen(x ".in", "r", stdin), freopen(x ".out", "w", stdout);

using namespace std;
namespace io {
const int SI = 1 << 21 | 1;
char IB[SI], *IS, *IT, OB[SI], *OS = OB, *OT = OS + SI - 1, c, ch[100];
int f, t;
#define gc()                                                                   \
  (IS == IT                                                                    \
       ? (IT = (IS = IB) + fread(IB, 1, SI, stdin), IS == IT ? EOF : *IS++)    \
       : *IS++)
inline void flush() { fwrite(OB, 1, OS - OB, stdout), OS = OB; }
inline void pc(char x) {
  *OS++ = x;
  if (OS == OT)
    flush();
}

template <class I> inline void rd(I &x) {
  for (f = 1, c = gc(); c < '0' || c > '9'; c = gc())
    if (c == '-')
      f = -1;
  for (x = 0; c >= '0' && c <= '9';
       x = (x << 3) + (x << 1) + (c & 15), c = gc())
    ;
  x *= f;
}
template <class I> inline void rd(I &x, I &y) { rd(x), rd(y); }
template <class I> inline void rd(I &x, I &y, I &z) { rd(x), rd(y), rd(z); }
template <class I> inline void rda(I *a, int n) {
  for (int i = 1; i <= n; i++)
    rd(a[i]);
}
inline void rdc(char &c) {
  for (c = gc(); c < 33 || c > 126; c = gc())
    ;
}
inline void rds(char *s, int &n) {
  for (c = gc(); c < 33 || c > 126; c = gc())
    ;
  for (n = 0; c >= 33 && c <= 126; s[++n] = c, c = gc())
    ;
  s[n + 1] = '\0';
}
inline void rds(string &s) {
  for (c = gc(); c < 33 || c > 126; c = gc())
    ;
  for (s.clear(); c >= 33 && c <= 126; s.pb(c), c = gc())
    ;
}

template <class I> inline void print(I x, char k = '\n') {
  if (!x)
    pc('0');
  if (x < 0)
    pc('-'), x = -x;
  while (x)
    ch[++t] = x % 10 + '0', x /= 10;
  while (t)
    pc(ch[t--]);
  pc(k);
}
template <class I> inline void print(I x, I y) { print(x, ' '), print(y); }
template <class I> inline void print(I x, I y, I z) {
  print(x, ' '), print(y, ' '), print(z);
}
template <class I> inline void printa(I *a, int n) {
  for (int i = 1; i <= n; i++)
    print(a[i], " \n"[i == n]);
}
inline void printc(char c) { pc(c); }
inline void prints(char *s, int n) {
  for (int i = 1; i <= n; i++)
    pc(s[i]);
  pc('\n');
}
inline void prints(string s) {
  int n = s.length();
  while (t < n)
    pc(s[t++]);
  pc('\n'), t = 0;
}
struct Flush {
  ~Flush() { flush(); }
} flusher;
} // namespace io
using io::print;
using io::printa;
using io::printc;
using io::prints;
using io::rd;
using io::rda;
using io::rdc;
using io::rds;

const int P = 1000000007;

struct modint {
  int x;
  inline modint(int x = 0) : x(x) {}
  inline modint &operator=(int o) { return x = o, *this; }
  inline modint &operator+=(modint o) {
    return x = x + o.x >= P ? x + o.x - P : x + o.x, *this;
  }
  inline modint &operator-=(modint o) {
    return x = x - o.x < 0 ? x - o.x + P : x - o.x, *this;
  }
  inline modint &operator*=(modint o) { return x = 1ll * x * o.x % P, *this; }
  inline modint &operator^=(ll b) {
    modint a = *this, c;
    if (!~b)
      b = P - 2;
    c.x = 1 % P;
    while (b) {
      if (b & 1)
        c *= a;
      a *= a, b >>= 1;
    }
    return x = c.x, *this;
  }
  inline modint &operator/=(modint o) { return *this *= o ^= -1; }
  inline modint &operator+=(int o) {
    return x = x + o >= P ? x + o - P : x + o, *this;
  }
  inline modint &operator-=(int o) {
    return x = x - o < 0 ? x - o + P : x - o, *this;
  }
  inline modint &operator*=(int o) { return x = 1ll * x * o % P, *this; }
  inline modint &operator/=(int o) {
    modint y = modint(o);
    return *this *= y ^= -1;
  }
  template <class I> inline friend modint operator+(modint a, I b) {
    return a += b;
  }
  template <class I> inline friend modint operator-(modint a, I b) {
    return a -= b;
  }
  template <class I> inline friend modint operator*(modint a, I b) {
    return a *= b;
  }
  inline friend modint operator^(modint a, ll b) { return a ^= b; }
  template <class I> inline friend modint operator/(modint a, I b) {
    return a /= b;
  }
  inline friend bool operator==(modint a, int b) { return a.x == b; }
  inline friend bool operator!=(modint a, int b) { return a.x != b; }
  inline friend bool operator<(modint a, int b) { return a.x < b; }
  inline friend bool operator<=(modint a, int b) { return a.x <= b; }
  inline friend bool operator>(modint a, int b) { return a.x > b; }
  inline friend bool operator>=(modint a, int b) { return a.x >= b; }
  inline friend bool operator==(modint a, modint b) { return a.x == b.x; }
  inline friend bool operator!=(modint a, modint b) { return a.x != b.x; }
  inline friend bool operator<(modint a, modint b) { return a.x < b.x; }
  inline friend bool operator<=(modint a, modint b) { return a.x <= b.x; }
  inline friend bool operator>(modint a, modint b) { return a.x > b.x; }
  inline friend bool operator>=(modint a, modint b) { return a.x >= b.x; }
  inline bool operator!() { return !x; }
  inline modint operator-() { return x ? P - x : 0; }
};
inline void rd(modint &x) { rd(x.x); }
inline void print(modint x, char k = '\n') { print(x.x, k); }
template <class T> inline void cmin(T &a, T b) { a = b < a ? b : a; }
template <class T> inline void cmax(T &a, T b) { a = b > a ? b : a; }
// head

const int N = 200010;
const int M = 57;

int n;
long double a[N];
ll g[N], tmp = 1000000000;
int c[M][M];
ll ans;

int main() {

  // fl("A");

  rd(n);
  for (int i = 1; i <= n; i++) {
    string s;
    rds(s);
    int p = -1;
    for (ui j = 0; j < s.size(); j++)
      if (s[j] == '.')
        p = j;
    if (!~p)
      p = s.size(), s += ".0";
    while ((int)s.size() - p < 10)
      s += "0";
    ll a = 0;
    for (ui j = 0; j < s.size(); j++)
      if (s[j] != '.')
        a = a * 10 + s[j] - '0';
    int c2 = 0, c5 = 0;
    while (a % 2 == 0)
      ++c2, a /= 2;
    while (a % 5 == 0)
      ++c5, a /= 5;
    c[c2][c5]++;
  }
  for (int i = 0; i < M; i++) {
    for (int j = 0; j < M; j++) {
      for (int k = max(0, 18 - i); k < M; k++) {
        for (int t = max(0, 18 - j); t < M; t++) {
          if (i == k && j == t)
            continue;
          ans += 1ll * c[i][j] * c[k][t];
        }
      }
    }
  }
  for (int i = 9; i < M; i++) {
    for (int j = 9; j < M; j++) {
      if (c[i][j]) {
        ans += 1ll * c[i][j] * (c[i][j] - 1);
      }
    }
  }
  print(ans / 2);

  return 0;
}