結果

問題 No.3056 Disconnected Coloring
ユーザー fuppy_kyopro
提出日時 2025-03-14 22:14:44
言語 C++17
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 169 ms / 2,000 ms
コード長 7,514 bytes
コンパイル時間 2,349 ms
コンパイル使用メモリ 209,336 KB
実行使用メモリ 20,340 KB
最終ジャッジ日時 2025-03-14 22:14:52
合計ジャッジ時間 7,554 ms
ジャッジサーバーID
（参考情報） 		judge2 / judge3
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 2
other AC * 34
権限があれば一括ダウンロードができます

ソースコード

diff # 

/*
#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
//*/

// #include <atcoder/all>
#include <atcoder/segtree>
#include <bits/stdc++.h>

using namespace std;
using namespace atcoder;

// #define _GLIBCXX_DEBUG
#ifdef LOCAL
#define DEBUG(x) cerr << #x << ": " << x << endl;
#define DEBUG_VEC(v)                                        \
    cerr << #v << ":";                                      \
    for (int iiiiiiii = 0; iiiiiiii < v.size(); iiiiiiii++) \
        cerr << " " << v[iiiiiiii];                         \
    cerr << endl;
#define DEBUG_MAT(v)                                \
    cerr << #v << endl;                             \
    for (int iv = 0; iv < v.size(); iv++) {         \
        for (int jv = 0; jv < v[iv].size(); jv++) { \
            cerr << v[iv][jv] << " ";               \
        }                                           \
        cerr << endl;                               \
    }
#else
#define DEBUG(x) ;
#define DEBUG_VEC(v) ;
#define DEBUG_MAT(v) ;
#endif
typedef long long ll;
// #define int ll

#define vi vector<int>
#define vl vector<ll>
#define vii vector<vector<int>>
#define vll vector<vector<ll>>
#define pii pair<int, int>
#define pis pair<int, string>
#define psi pair<string, int>
#define pll pair<ll, ll>
template <class S, class T>
pair<S, T> operator+(const pair<S, T> &s, const pair<S, T> &t) {
    return pair<S, T>(s.first + t.first, s.second + t.second);
}
template <class S, class T>
pair<S, T> operator-(const pair<S, T> &s, const pair<S, T> &t) { return pair<S, T>(s.first - t.first, s.second - t.second); }
template <class S, class T>
ostream &operator<<(ostream &os, pair<S, T> p) {
    os << "(" << p.first << ", " << p.second << ")";
    return os;
}
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define rep1(i, n) for (int i = 1; i <= (int)(n); i++)
#define rrep(i, n) for (int i = (int)(n) - 1; i >= 0; i--)
#define rrep1(i, n) for (int i = (int)(n); i > 0; i--)
#define REP(i, a, b) for (int i = a; i < b; i++)
#define in(x, a, b) (a <= x && x < b)
#define all(c) c.begin(), c.end()
void YES(bool t = true) {
    cout << (t ? "YES" : "NO") << endl;
}
void Yes(bool t = true) { cout << (t ? "Yes" : "No") << endl; }
void yes(bool t = true) { cout << (t ? "yes" : "no") << endl; }
void NO(bool t = true) { cout << (t ? "NO" : "YES") << endl; }
void No(bool t = true) { cout << (t ? "No" : "Yes") << endl; }
void no(bool t = true) { cout << (t ? "no" : "yes") << endl; }
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 (a > b) {
        a = b;
        return 1;
    }
    return 0;
}
template <class T, class U>
T ceil_div(T a, U b) {
    return (a + b - 1) / b;
}
template <class T>
T safe_mul(T a, T b) {
    if (a == 0 || b == 0) return 0;
    if (numeric_limits<T>::max() / a < b) return numeric_limits<T>::max();
    return a * b;
}
#define UNIQUE(v) v.erase(std::unique(v.begin(), v.end()), v.end());
const ll inf = 1000000001;
const ll INF = (ll)1e18 + 1;
const long double pi = 3.1415926535897932384626433832795028841971L;
int popcount(ll t) { return __builtin_popcountll(t); }
vector<int> gen_perm(int n) {
    vector<int> ret(n);
    iota(all(ret), 0);
    return ret;
}
// int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};
// int dx2[8] = { 1,1,0,-1,-1,-1,0,1 }, dy2[8] = { 0,1,1,1,0,-1,-1,-1 };
vi dx = {0, 0, -1, 1}, dy = {-1, 1, 0, 0};
vi dx2 = {1, 1, 0, -1, -1, -1, 0, 1}, dy2 = {0, 1, 1, 1, 0, -1, -1, -1};
struct Setup_io {
    Setup_io() {
        ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
        cout << fixed << setprecision(25);
        cerr << fixed << setprecision(25);
    }
} setup_io;
// constexpr ll MOD = 1000000007;
constexpr ll MOD = 998244353;
// #define mp make_pair

struct dice {
    mt19937 mt;
    dice() : mt(chrono::steady_clock::now().time_since_epoch().count()) {}
    // [0, x)の一様乱数
    ll operator()(ll x) { return this->operator()(0, x); }
    // [x, y)の一様乱数
    ll operator()(ll x, ll y) {
        uniform_int_distribution<ll> dist(x, y - 1);
        return dist(mt);
    }
    vl operator()(int n, ll x, ll y) {
        vl res(n);
        for (int i = 0; i < n; i++)
            res[i] = this->operator()(x, y);
        return res;
    }
} rnd;

std::random_device seed_gen;
std::mt19937 engine(seed_gen());

class UnionFind {
  private:
    vi par_;
    vi ran_;
    vi num_;
    vi edge_num_;

  public:
    int n;
    int g; // group

    UnionFind(int _n) {
        n = _n;
        g = n;
        par_.resize(n);
        ran_.resize(n);
        num_.resize(n);
        edge_num_.resize(n);
        for (int i = 0; i < n; i++) {
            par_[i] = i;
            ran_[i] = 0;
            num_[i] = 1;
            edge_num_[i] = 0;
        }
    }

    int find(int x) {
        if (par_[x] == x) {
            return x;
        } else {
            return par_[x] = find(par_[x]);
        }
    }

    void unite(int x, int y) {
        x = find(x);
        y = find(y);
        int numsum = num_[x] + num_[y];
        int edge_numsum = edge_num_[x] + edge_num_[y];
        if (x == y) {
            edge_num_[x]++;
            return;
        }
        if (ran_[x] < ran_[y]) {
            par_[x] = y;
        } else {
            par_[y] = x;
            if (ran_[x] == ran_[y]) {
                ran_[x]++;
            }
        }
        num_[x] = num_[y] = numsum;
        edge_num_[x] = edge_num_[y] = edge_numsum + 1;
        g--;
    }

    bool same(int x, int y) {
        return find(x) == find(y);
    }

    int num(int x) {
        return num_[find(x)];
    }

    int edge_num(int x) {
        return edge_num_[find(x)];
    }
};

auto start_time = chrono::system_clock::now();

signed main() {
    int n, m;
    cin >> n >> m;

    vector<pii> es;
    rep(i, m) {
        int a, b;
        cin >> a >> b;
        a--;
        b--;
        es.push_back({a, b});
    }

    if (m % 2 == 1) {
        cout << -1 << endl;
        return 0;
    }

    for (auto [u, v] : es) {
        if (u == 0 && v == n - 1) {
            cout << -1 << endl;
            return 0;
        }
    }

    vii G(n);
    for (auto [u, v] : es) {
        G[u].push_back(v);
        G[v].push_back(u);
    }

    vi ignore(n);
    vi roots = {0, n - 1};
    for (int r : roots) {
        UnionFind uf(n);
        rep(u, n) {
            for (int v : G[u]) {
                if (u == r || v == r) {
                    continue;
                }
                uf.unite(u, v);
            }
        }

        int tar;
        if (r == 0) {
            tar = n - 1;
        } else {
            tar = 0;
        }

        for (int u = 1; u < n - 1; u++) {
            if (!uf.same(u, tar)) {
                ignore[u] = 1;
            }
        }
    }

    string s(m, '?');
    int r_rem = m / 2, b_rem = m / 2;
    rep(i, m) {
        auto [u, v] = es[i];
        if (ignore[u] || ignore[v]) {
            continue;
        }

        if (u == 0) {
            s[i] = 'R';
            r_rem--;
        } else if (v == n - 1) {
            s[i] = 'B';
            b_rem--;
        }
    }

    assert(r_rem >= 0 && b_rem >= 0);
    rep(i, m) {
        if (s[i] == '?') {
            if (r_rem > 0) {
                s[i] = 'R';
                r_rem--;
            } else {
                s[i] = 'B';
                b_rem--;
            }
        }
    }

    cout << s << endl;
}
0