Problem p02692 (C++)

Buggy submission (status: Runtime Error):
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vb = vector<bool>;
using vvb = vector<vb>;
using vd = vector<double>;
using vvd = vector<vd>;
using vi = vector<int>;
using vvi = vector<vi>;
using vl = vector<ll>;
using vvl = vector<vl>;
using pll = pair<ll, ll>;
using tll = tuple<ll, ll>;
using tlll = tuple<ll, ll, ll>;
using vs = vector<string>;
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define rep(i, n) range(i, 0, n)
#define rrep(i, n) for (ll i = ((ll)n) - 1; i >= 0; i--)
#define range(i, a, n) for (ll i = ((ll)a); i < ((ll)n); i++)
#define LINF ((ll)1ll << 60)
#define INF ((int)1 << 30)
#define EPS (1e-9)
#define MOD (1000000007ll)
#define fcout(a) cout << setprecision(a) << fixed
#define fs first
#define sc second
#define PI (3.1415926535897932384)

int dx[] = {1, 0, -1, 0, 1, -1, -1, 1}, dy[] = {0, 1, 0, -1, 1, 1, -1, -1};
template <class T> bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
template <class T> bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
template <class S> S sum(vector<S> &a) { return accumulate(all(a), S()); }
template <class S> S max(vector<S> &a) { return *max_element(all(a)); }
template <class S> S min(vector<S> &a) { return *min_element(all(a)); }
ll max(int a, ll b) { return max((ll)a, b); }
ll max(ll a, int b) { return max(a, (ll)b); }
int sgn(const double &r) { return (r > EPS) - (r < -EPS); } // a>0  : sgn(a)>0
int sgn(const double &a, const double &b) {
  return sgn(a - b);
} // b<=c : sgn(b,c)<=0

template <class T> void puta(T &&t) { cout << t << "\n"; }
template <class H, class... T> void puta(H &&h, T &&...t) {
  cout << h << ' ';
  puta(t...);
}
template <class S, class T> void tf(bool b, S t, T f) {
  if (b)
    puta(t);
  else
    puta(f);
}
void YN(bool b) { tf(b, "YES", "NO"); }
void Yn(bool b) { tf(b, "Yes", "No"); }
void yn(bool b) { tf(b, "yes", "no"); }
template <class S, class T> ostream &operator<<(ostream &os, pair<S, T> p) {
  os << "[" << p.first << ", " << p.second << "]";
  return os;
};
template <class S> auto &operator<<(ostream &os, vector<S> t) {
  bool a = 1;
  for (auto s : t) {
    os << (a ? "" : " ") << s;
    a = 0;
  }
  return os;
}
template <class S> auto &operator>>(istream &is, vector<S> &t) {
  for (S &a : t)
    cin >> a;
  return is;
}

/*他のライブラリを入れる場所*/

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  ll n, a, b, c;
  cin >> n >> a >> b >> c;
  vs s(n);
  cin >> s;
  if (a + b + c == 0) {
    puta("No");
    return 0;
  }

  vl v{a, b, c};
  vector<char> ans;
  vs other{"BC", "AC", "AB"};
  rep(i, n) {
    ll x = s[i][0] - 'A';
    ll y = s[i][1] - 'A';
    if (/*!v[0] + !v[1] + !v[2] == 2 and */ v[x] == 0 and v[y] == 0) {
      puta("No");
      return 0;
    } else {
      if (v[x] <= v[y]) {
        if (v[y] == 1) {
          if (i + 1 != n and s[i + 1] == other[x]) {
            v[x]--;
            v[y]++;
            ans.push_back((char)('A' + y));
          }
        } else {
          v[x]++;
          v[y]--;
          ans.push_back((char)('A' + x));
        }
      } else {
        v[x]--;
        v[y]++;
        ans.push_back((char)('A' + y));
      }
    }
  }
  puta("Yes");
  rep(i, n) puta(ans[i]);

  return 0;
}

Fixed submission:
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vb = vector<bool>;
using vvb = vector<vb>;
using vd = vector<double>;
using vvd = vector<vd>;
using vi = vector<int>;
using vvi = vector<vi>;
using vl = vector<ll>;
using vvl = vector<vl>;
using pll = pair<ll, ll>;
using tll = tuple<ll, ll>;
using tlll = tuple<ll, ll, ll>;
using vs = vector<string>;
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define rep(i, n) range(i, 0, n)
#define rrep(i, n) for (ll i = ((ll)n) - 1; i >= 0; i--)
#define range(i, a, n) for (ll i = ((ll)a); i < ((ll)n); i++)
#define LINF ((ll)1ll << 60)
#define INF ((int)1 << 30)
#define EPS (1e-9)
#define MOD (1000000007ll)
#define fcout(a) cout << setprecision(a) << fixed
#define fs first
#define sc second
#define PI (3.1415926535897932384)

int dx[] = {1, 0, -1, 0, 1, -1, -1, 1}, dy[] = {0, 1, 0, -1, 1, 1, -1, -1};
template <class T> bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
template <class T> bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
template <class S> S sum(vector<S> &a) { return accumulate(all(a), S()); }
template <class S> S max(vector<S> &a) { return *max_element(all(a)); }
template <class S> S min(vector<S> &a) { return *min_element(all(a)); }
ll max(int a, ll b) { return max((ll)a, b); }
ll max(ll a, int b) { return max(a, (ll)b); }
int sgn(const double &r) { return (r > EPS) - (r < -EPS); } // a>0  : sgn(a)>0
int sgn(const double &a, const double &b) {
  return sgn(a - b);
} // b<=c : sgn(b,c)<=0

template <class T> void puta(T &&t) { cout << t << "\n"; }
template <class H, class... T> void puta(H &&h, T &&...t) {
  cout << h << ' ';
  puta(t...);
}
template <class S, class T> void tf(bool b, S t, T f) {
  if (b)
    puta(t);
  else
    puta(f);
}
void YN(bool b) { tf(b, "YES", "NO"); }
void Yn(bool b) { tf(b, "Yes", "No"); }
void yn(bool b) { tf(b, "yes", "no"); }
template <class S, class T> ostream &operator<<(ostream &os, pair<S, T> p) {
  os << "[" << p.first << ", " << p.second << "]";
  return os;
};
template <class S> auto &operator<<(ostream &os, vector<S> t) {
  bool a = 1;
  for (auto s : t) {
    os << (a ? "" : " ") << s;
    a = 0;
  }
  return os;
}
template <class S> auto &operator>>(istream &is, vector<S> &t) {
  for (S &a : t)
    cin >> a;
  return is;
}

/*他のライブラリを入れる場所*/

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  ll n, a, b, c;
  cin >> n >> a >> b >> c;
  vs s(n);
  cin >> s;
  if (a + b + c == 0) {
    puta("No");
    return 0;
  }

  vl v{a, b, c};
  vector<char> ans;
  vs other{"BC", "AC", "AB"};
  rep(i, n) {
    ll x = s[i][0] - 'A';
    ll y = s[i][1] - 'A';
    if (/*!v[0] + !v[1] + !v[2] == 2 and */ v[x] == 0 and v[y] == 0) {
      puta("No");
      return 0;
    } else {
      if (v[x] <= v[y]) {
        if (v[x] == 1 and v[y] == 1 and i + 1 != n and s[i + 1] == other[x]) {
          v[x]--;
          v[y]++;
          ans.push_back((char)('A' + y));
        } else {
          v[x]++;
          v[y]--;
          ans.push_back((char)('A' + x));
        }
      } else {
        v[x]--;
        v[y]++;
        ans.push_back((char)('A' + y));
      }
    }
  }
  puta("Yes");
  rep(i, n) puta(ans[i]);

  return 0;
}