Problem p02762 (C++)

Buggy submission (status: Runtime Error):
#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
using namespace std;
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
typedef long long ll;
const ll MOD = 1e9 + 7;
#define rep(i, n) for (int i = 0, i##_len = (n); i < i##_len; ++i)
#define REP(i, num, n) for (int i = num, i##_len = (n); i < i##_len; ++i)
template <class T> bool chmax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> bool chmin(T &a, const T &b) {
  if (b < a) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> inline void add(T &a, T b) {
  a = ((a + b) % MOD + MOD) % MOD;
};
#define print(x) (cout << (x) << endl)
#define pb push_back
#define mp make_pair
#define sz(x) int(x.size())
#define fs first
#define sc second

const int INF = 1e9;
const ll LLINF = 1e16;

template <typename T> vector<T> make_v(size_t a) { return vector<T>(a); }

template <typename T, typename... Ts> auto make_v(size_t a, Ts... ts) {
  return vector<decltype(make_v<T>(ts...))>(a, make_v<T>(ts...));
}

template <typename T, typename U, typename... V>
typename enable_if<is_same<T, U>::value != 0>::type fill_v(U &u, const V... v) {
  u = U(v...);
}

template <typename T, typename U, typename... V>
typename enable_if<is_same<T, U>::value == 0>::type fill_v(U &u, const V... v) {
  for (auto &e : u)
    fill_v<T>(e, v...);
}

template <typename T> T gcd(T a, T b) { return b ? gcd(b, a % b) : a; }

template <typename T> T ngcd(vector<T> a) {
  T res;
  res = a[0];
  for (int i = 1; i < a.size() && res != 1; i++) {
    res = gcd(a[i], res);
  }
  return res;
}

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

template <typename T> T nlcm(vector<T> numbers) {
  T res;
  res = numbers[0];
  for (int i = 1; i < numbers.size(); i++) {
    res = lcm(res, numbers[i]);
  }
  return res;
}

// 割り算の切り上げ処理
template <typename T> T round_up(T a, T b) { return (a + b - 1) / b; }

// 約数列挙
template <typename T> vector<T> calc_divisor(T n) {
  vector<T> res;
  for (T i = 1LL; i * i <= n; ++i) {
    if (n % i == 0) {
      res.push_back(i);
      T j = n / i;
      if (j != i)
        res.push_back(j);
    }
  }
  sort(res.begin(), res.end());
  return res;
}

// 素数判定
template <typename T> bool isPrime(T x) {
  T i;
  if (x < 2)
    return 0;
  else if (x == 2)
    return 1;
  if (x % 2 == 0)
    return 0;
  for (i = 3; i * i <= x; i += 2)
    if (x % i == 0)
      return 0;
  return 1;
}

// 桁和
template <typename T> T digsum(T n) {
  T res = 0;
  while (n > 0) {
    res += n % 10;
    n /= 10;
  }
  return res;
}

// 指定した文字cが文字列に何文字入ってるか
ll stringcount(string s, char c) { return count(s.cbegin(), s.cend(), c); }

using pint = pair<int, int>;
using pll = pair<ll, ll>;

struct UnionFind {
  vector<int> par;

  UnionFind(int n) : par(n, -1) {}
  void init(int n) { par.assign(n, -1); }

  int root(int x) {
    if (par[x] < 0)
      return x;
    else
      return par[x] = root(par[x]);
  }

  bool issame(int x, int y) { return root(x) == root(y); }

  bool merge(int x, int y) {
    x = root(x);
    y = root(y);
    if (x == y)
      return false;
    if (par[x] > par[y])
      swap(x, y); // merge technique
    par[x] += par[y];
    par[y] = x;
    return true;
  }

  int size(int x) { return -par[root(x)]; }
};

int deg[100005];
vector<int> to[100005];

int main(void) {
  cout.tie(0);
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << fixed << setprecision(10);
  int n, m, k;
  cin >> n >> m >> k;
  UnionFind uf(m);

  rep(i, m) {
    int a, b;
    cin >> a >> b;
    --a;
    --b;
    deg[a]++;
    deg[b]++;
    uf.merge(a, b);
  }
  rep(i, k) {
    int c, d;
    cin >> c >> d;
    --c;
    --d;
    to[c].push_back(d);
    to[d].push_back(c);
  }
  rep(i, n) {
    int ans = uf.size(i) - 1 - deg[i];
    for (int u : to[i]) {
      if (uf.issame(i, u))
        --ans;
    }
    print(ans);
  }
}


Fixed submission:
#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
using namespace std;
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
typedef long long ll;
const ll MOD = 1e9 + 7;
#define rep(i, n) for (int i = 0, i##_len = (n); i < i##_len; ++i)
#define REP(i, num, n) for (int i = num, i##_len = (n); i < i##_len; ++i)
template <class T> bool chmax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> bool chmin(T &a, const T &b) {
  if (b < a) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> inline void add(T &a, T b) {
  a = ((a + b) % MOD + MOD) % MOD;
};
#define print(x) (cout << (x) << endl)
#define pb push_back
#define mp make_pair
#define sz(x) int(x.size())
#define fs first
#define sc second

const int INF = 1e9;
const ll LLINF = 1e16;

template <typename T> vector<T> make_v(size_t a) { return vector<T>(a); }

template <typename T, typename... Ts> auto make_v(size_t a, Ts... ts) {
  return vector<decltype(make_v<T>(ts...))>(a, make_v<T>(ts...));
}

template <typename T, typename U, typename... V>
typename enable_if<is_same<T, U>::value != 0>::type fill_v(U &u, const V... v) {
  u = U(v...);
}

template <typename T, typename U, typename... V>
typename enable_if<is_same<T, U>::value == 0>::type fill_v(U &u, const V... v) {
  for (auto &e : u)
    fill_v<T>(e, v...);
}

template <typename T> T gcd(T a, T b) { return b ? gcd(b, a % b) : a; }

template <typename T> T ngcd(vector<T> a) {
  T res;
  res = a[0];
  for (int i = 1; i < a.size() && res != 1; i++) {
    res = gcd(a[i], res);
  }
  return res;
}

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

template <typename T> T nlcm(vector<T> numbers) {
  T res;
  res = numbers[0];
  for (int i = 1; i < numbers.size(); i++) {
    res = lcm(res, numbers[i]);
  }
  return res;
}

// 割り算の切り上げ処理
template <typename T> T round_up(T a, T b) { return (a + b - 1) / b; }

// 約数列挙
template <typename T> vector<T> calc_divisor(T n) {
  vector<T> res;
  for (T i = 1LL; i * i <= n; ++i) {
    if (n % i == 0) {
      res.push_back(i);
      T j = n / i;
      if (j != i)
        res.push_back(j);
    }
  }
  sort(res.begin(), res.end());
  return res;
}

// 素数判定
template <typename T> bool isPrime(T x) {
  T i;
  if (x < 2)
    return 0;
  else if (x == 2)
    return 1;
  if (x % 2 == 0)
    return 0;
  for (i = 3; i * i <= x; i += 2)
    if (x % i == 0)
      return 0;
  return 1;
}

// 桁和
template <typename T> T digsum(T n) {
  T res = 0;
  while (n > 0) {
    res += n % 10;
    n /= 10;
  }
  return res;
}

// 指定した文字cが文字列に何文字入ってるか
ll stringcount(string s, char c) { return count(s.cbegin(), s.cend(), c); }

using pint = pair<int, int>;
using pll = pair<ll, ll>;

struct UnionFind {
  vector<int> par;

  UnionFind(int n) : par(n, -1) {}
  void init(int n) { par.assign(n, -1); }

  int root(int x) {
    if (par[x] < 0)
      return x;
    else
      return par[x] = root(par[x]);
  }

  bool issame(int x, int y) { return root(x) == root(y); }

  bool merge(int x, int y) {
    x = root(x);
    y = root(y);
    if (x == y)
      return false;
    if (par[x] > par[y])
      swap(x, y); // merge technique
    par[x] += par[y];
    par[y] = x;
    return true;
  }

  int size(int x) { return -par[root(x)]; }
};

int deg[100005];
vector<int> to[100005];

int main(void) {
  cout.tie(0);
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << fixed << setprecision(10);
  int n, m, k;
  cin >> n >> m >> k;
  UnionFind uf(n);

  rep(i, m) {
    int a, b;
    cin >> a >> b;
    --a;
    --b;
    deg[a]++;
    deg[b]++;
    uf.merge(a, b);
  }
  rep(i, k) {
    int c, d;
    cin >> c >> d;
    --c;
    --d;
    to[c].push_back(d);
    to[d].push_back(c);
  }
  rep(i, n) {
    int ans = uf.size(i) - 1 - deg[i];
    for (int u : to[i]) {
      if (uf.issame(i, u))
        --ans;
    }
    print(ans);
  }
}