Problem p03329 (C++)

Buggy submission (status: Time Limit Exceeded):
#include <bits/stdc++.h>
#define fi first
#define se second
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rrep(i, n) for (int i = 1; i <= (n); ++i)
#define drep(i, n) for (int i = (n)-1; i >= 0; --i)
#define srep(i, s, t) for (int i = s; i < t; ++i)
#define rng(a) a.begin(), a.end()
#define maxs(x, y) (x = max(x, y))
#define mins(x, y) (x = min(x, y))
#define limit(x, l, r) max(l, min(x, r))
#define lims(x, l, r) (x = max(l, min(x, r)))
#define isin(x, l, r) ((l) <= (x) && (x) < (r))
#define pb push_back
#define sz(x) (int)(x).size()
#define pcnt __builtin_popcountll
#define uni(x) x.erase(unique(rng(x)), x.end())
#define snuke srand((unsigned)clock() + (unsigned)time(NULL));
#define show(x) cout << #x << " = " << x << endl;
#define PQ(T) priority_queue<T, v(T), greater<T>>
#define bn(x) ((1 << x) - 1)
#define dup(x, y) (((x) + (y)-1) / (y))
#define newline puts("")
#define v(T) vector<T>
#define vv(T) v(v(T))
using namespace std;
typedef long long int ll;
typedef unsigned uint;
typedef unsigned long long ull;
typedef pair<int, int> P;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<ll> vl;
typedef vector<P> vp;
inline int in() {
  int x;
  scanf("%d", &x);
  return x;
}
template <typename T> inline istream &operator>>(istream &i, v(T) & v) {
  rep(j, sz(v)) i >> v[j];
  return i;
}
template <typename T> string join(const v(T) & v) {
  stringstream s;
  rep(i, sz(v)) s << ' ' << v[i];
  return s.str().substr(1);
}
template <typename T> inline ostream &operator<<(ostream &o, const v(T) & v) {
  if (sz(v))
    o << join(v);
  return o;
}
template <typename T1, typename T2>
inline istream &operator>>(istream &i, pair<T1, T2> &v) {
  return i >> v.fi >> v.se;
}
template <typename T1, typename T2>
inline ostream &operator<<(ostream &o, const pair<T1, T2> &v) {
  return o << v.fi << "," << v.se;
}
template <typename T> inline ll suma(const v(T) & a) {
  ll res(0);
  for (auto &&x : a)
    res += x;
  return res;
}
const double eps = 1e-10;
const ll LINF = 1001002003004005006ll;
const int INF = 1001001001;
#define dame                                                                   \
  {                                                                            \
    puts("-1");                                                                \
    return 0;                                                                  \
  }
#define yn                                                                     \
  { puts("Yes"); }                                                             \
  else {                                                                       \
    puts("No");                                                                \
  }
const int MX = 200005;

// 整数スキャン（複数）
/*
int x;
scanf("%d",&x);
int y;
scanf("%d",&y);
int z;
scanf("%d",&z);

// n個の整数のスキャン
/*
ll a[n] = {};
rep(i,n){
    scanf("%lld",&a[i]);
}
*/

// 文字列スキャン
/*
string s;
cin >> s;
*/

// n個の文字列スキャン
/*
vector<string> slist;
rep(i,n){
    string s;
    cin >> s;
    slist.push_back(s);
}
*/

int main() {
  int n;
  scanf("%d", &n);
  if (n <= 5) {
    cout << n << endl;
    return 0;
  }
  int ans = 0;
  ans += n % 3;
  n -= n % 3;
  if (n == 6) {
    cout << ans + 1 << endl;
    return 0;
  } else if (n == 9) {
    cout << ans + 1 << endl;
    return 0;
  }
  int a[7] = {};
  int aa[7] = {};
  int six = 6;
  int nin = 9;
  rep(i, 7) {
    a[i] = six;
    six *= 6;
    aa[i] = nin;
    nin *= 9;
  }

  // ここでnは12以上の3の倍数
  int n9 = n;
  int n6 = 0;
  if (n9 % 9 == 3) {
    n9 -= 12;
    n6 += 12;
  } else {
    n9 -= 6;
    n6 += 6;
  }
  int s[10000][2];
  int count = 0;
  while (n9 >= 0) {
    int nn9 = n9;
    int c9 = 0;
    int nn6 = n6;
    int c6 = 0;
    while (nn6 > 0) {
      drep(i, 7) {
        if (nn6 >= a[i]) {
          c6++;
          nn6 -= a[i];
          break;
        }
      }
    }
    while (nn9 > 0) {
      drep(i, 7) {
        if (nn9 >= aa[i]) {
          c9++;
          nn9 -= aa[i];
          break;
        }
      }
    }
    s[count][0] = c6;
    s[count][1] = c9;
    count++;
    n9 -= 18;
    n6 += 18;
  }
  int mmm = 99999;
  rep(i, count) { mins(mmm, s[i][0] + s[i][1]); }

  cout << ans + mmm << endl;
  return 0;
}


Fixed submission:
#include <bits/stdc++.h>
#define fi first
#define se second
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rrep(i, n) for (int i = 1; i <= (n); ++i)
#define drep(i, n) for (int i = (n)-1; i >= 0; --i)
#define srep(i, s, t) for (int i = s; i < t; ++i)
#define rng(a) a.begin(), a.end()
#define maxs(x, y) (x = max(x, y))
#define mins(x, y) (x = min(x, y))
#define limit(x, l, r) max(l, min(x, r))
#define lims(x, l, r) (x = max(l, min(x, r)))
#define isin(x, l, r) ((l) <= (x) && (x) < (r))
#define pb push_back
#define sz(x) (int)(x).size()
#define pcnt __builtin_popcountll
#define uni(x) x.erase(unique(rng(x)), x.end())
#define snuke srand((unsigned)clock() + (unsigned)time(NULL));
#define show(x) cout << #x << " = " << x << endl;
#define PQ(T) priority_queue<T, v(T), greater<T>>
#define bn(x) ((1 << x) - 1)
#define dup(x, y) (((x) + (y)-1) / (y))
#define newline puts("")
#define v(T) vector<T>
#define vv(T) v(v(T))
using namespace std;
typedef long long int ll;
typedef unsigned uint;
typedef unsigned long long ull;
typedef pair<int, int> P;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<ll> vl;
typedef vector<P> vp;
inline int in() {
  int x;
  scanf("%d", &x);
  return x;
}
template <typename T> inline istream &operator>>(istream &i, v(T) & v) {
  rep(j, sz(v)) i >> v[j];
  return i;
}
template <typename T> string join(const v(T) & v) {
  stringstream s;
  rep(i, sz(v)) s << ' ' << v[i];
  return s.str().substr(1);
}
template <typename T> inline ostream &operator<<(ostream &o, const v(T) & v) {
  if (sz(v))
    o << join(v);
  return o;
}
template <typename T1, typename T2>
inline istream &operator>>(istream &i, pair<T1, T2> &v) {
  return i >> v.fi >> v.se;
}
template <typename T1, typename T2>
inline ostream &operator<<(ostream &o, const pair<T1, T2> &v) {
  return o << v.fi << "," << v.se;
}
template <typename T> inline ll suma(const v(T) & a) {
  ll res(0);
  for (auto &&x : a)
    res += x;
  return res;
}
const double eps = 1e-10;
const ll LINF = 1001002003004005006ll;
const int INF = 1001001001;
#define dame                                                                   \
  {                                                                            \
    puts("-1");                                                                \
    return 0;                                                                  \
  }
#define yn                                                                     \
  { puts("Yes"); }                                                             \
  else {                                                                       \
    puts("No");                                                                \
  }
const int MX = 200005;

// 整数スキャン（複数）
/*
int x;
scanf("%d",&x);
int y;
scanf("%d",&y);
int z;
scanf("%d",&z);

// n個の整数のスキャン
/*
ll a[n] = {};
rep(i,n){
    scanf("%lld",&a[i]);
}
*/

// 文字列スキャン
/*
string s;
cin >> s;
*/

// n個の文字列スキャン
/*
vector<string> slist;
rep(i,n){
    string s;
    cin >> s;
    slist.push_back(s);
}
*/

int main() {
  int n;
  scanf("%d", &n);
  if (n <= 5) {
    cout << n << endl;
    return 0;
  }
  int ans = 0;
  ans += n % 3;
  n -= n % 3;
  if (n == 6) {
    cout << ans + 1 << endl;
    return 0;
  } else if (n == 9) {
    cout << ans + 1 << endl;
    return 0;
  }
  int a[7] = {};
  int aa[7] = {};
  int six = 6;
  int nin = 9;
  rep(i, 7) {
    a[i] = six;
    six *= 6;
    aa[i] = nin;
    nin *= 9;
  }

  // ここでnは12以上の3の倍数
  int n9 = n;
  int n6 = 0;
  if (n9 % 9 == 3) {
    n9 -= 12;
    n6 += 12;
  } else if (n9 % 9 == 6) {
    n9 -= 6;
    n6 += 6;
  }
  int s[10000][2];
  int count = 0;
  while (n9 >= 0) {
    int nn9 = n9;
    int c9 = 0;
    int nn6 = n6;
    int c6 = 0;
    while (nn6 > 0) {
      drep(i, 7) {
        if (nn6 >= a[i]) {
          c6++;
          nn6 -= a[i];
          break;
        }
      }
    }
    while (nn9 > 0) {
      drep(i, 7) {
        if (nn9 >= aa[i]) {
          c9++;
          nn9 -= aa[i];
          break;
        }
      }
    }
    s[count][0] = c6;
    s[count][1] = c9;
    count++;
    n9 -= 18;
    n6 += 18;
  }
  int mmm = 99999;
  rep(i, count) { mins(mmm, s[i][0] + s[i][1]); }

  cout << ans + mmm << endl;
  return 0;
}