#1015516 (C++17) No.2914 正閉路検出

• 問題: No.2914 正閉路検出
• ユーザー: dyktr_06
• 提出日時: 2024-10-04 23:14:17
• 言語: C++17 (gcc 13.3.0 + boost 1.87.0)
• 結果: AC
• 実行時間: 310 ms / 2,000 ms
• コード長: 8,468 bytes
• コンパイル時間: 5,001 ms
• コンパイル使用メモリ: 273,428 KB
• 最終ジャッジ日時: 2025-02-24 15:37:08
• ジャッジサーバーID （参考情報）: judge5 / judge5

ファイルパターン	結果
other	AC * 55

ソースコード

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

using namespace std;
using namespace atcoder;

#define overload4(_1, _2, _3, _4, name, ...) name
#define rep1(n) for(int i = 0; i < (int)(n); ++i)
#define rep2(i, n) for(int i = 0; i < (int)(n); ++i)
#define rep3(i, a, b) for(int i = (a); i < (int)(b); ++i)
#define rep4(i, a, b, c) for(int i = (a); i < (int)(b); i += (c))
#define rep(...) overload4(__VA_ARGS__, rep4, rep3, rep2, rep1)(__VA_ARGS__)

#define rrep(i,n) for(int i = (int)(n) - 1; i >= 0; --i)
#define ALL(a) (a).begin(), (a).end()
#define Sort(a) (sort((a).begin(), (a).end()))
#define RSort(a) (sort((a).rbegin(), (a).rend()))
#define UNIQUE(a) (a.erase(unique((a).begin(), (a).end()), (a).end()))

typedef long long int ll;
typedef unsigned long long ul;
typedef long double ld;
typedef vector<int> vi;
typedef vector<long long> vll;
typedef vector<char> vc;
typedef vector<string> vst;
typedef vector<double> vd;
typedef vector<long double> vld;
typedef pair<long long, long long> P;

template<class T> long long sum(const T &a){ return accumulate(a.begin(), a.end(), 0LL); }
template<class T> auto min(const T &a){ return *min_element(a.begin(), a.end()); }
template<class T> auto max(const T &a){ return *max_element(a.begin(), a.end()); }

const long long MINF = 0x7fffffffffff;
const long long INF = 0x1fffffffffffffff;
const long long MOD = 998244353;
const long double EPS = 1e-9;
const long double PI = acos(-1);

template<class T> inline bool chmax(T &a, T b) { if(a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T &a, T b) { if(a > b) { a = b; return 1; } return 0; }

template<typename T1, typename T2> istream &operator>>(istream &is, pair<T1, T2> &p){ is >> p.first >> p.second; return is; }
template<typename T1, typename T2> ostream &operator<<(ostream &os, const pair<T1, T2> &p){ os << "(" << p.first << ", " << p.second << ")"; return os; }
template<typename T> istream &operator>>(istream &is, vector<T> &v){ for(T &in : v) is >> in; return is; }
template<typename T> ostream &operator<<(ostream &os, const vector<T> &v){ for(int i = 0; i < (int) v.size(); ++i){ os << v[i] << (i + 1 != (int) v.size() ? " " : ""); } return os; }
template <typename T, typename S> ostream &operator<<(ostream &os, const map<T, S> &mp){ for(auto &[key, val] : mp){ os << key << ":" << val << " "; } return os; }
template <typename T> ostream &operator<<(ostream &os, const set<T> &st){ auto itr = st.begin(); for(int i = 0; i < (int) st.size(); ++i){ os << *itr << (i + 1 != (int) st.size() ? " " : ""); itr++; } return os; }
template <typename T> ostream &operator<<(ostream &os, const multiset<T> &st){ auto itr = st.begin(); for(int i = 0; i < (int) st.size(); ++i){ os << *itr << (i + 1 != (int) st.size() ? " " : ""); itr++; } return os; }
template <typename T> ostream &operator<<(ostream &os, queue<T> q){ while(q.size()){ os << q.front() << " "; q.pop(); } return os; }
template <typename T> ostream &operator<<(ostream &os, deque<T> q){ while(q.size()){ os << q.front() << " "; q.pop_front(); } return os; }
template <typename T> ostream &operator<<(ostream &os, stack<T> st){ while(st.size()){ os << st.top() << " "; st.pop(); } return os; }
template <class T, class Container, class Compare> ostream &operator<<(ostream &os, priority_queue<T, Container, Compare> pq){ while(pq.size()){ os << pq.top() << " "; pq.pop(); } return os; }

template <typename T>
long long binary_search(long long ok, long long ng, T check){
    while(abs(ok - ng) > 1){
        long long mid = (ok + ng) / 2;
        if(check(mid)) ok = mid;
        else ng = mid;
    }
    return ok;
}

template <typename T>
long double binary_search_real(long double ok, long double ng, T check, int iter = 100){
    for(int i = 0; i < iter; ++i){
        long double mid = (ok + ng) / 2;
        if(check(mid)) ok = mid;
        else ng = mid;
    }
    return ok;
}

template <typename T>
long long trisum(T a, T b){
    long long res = ((b - a + 1) * (a + b)) / 2;
    return res;
}

template <typename T>
T intpow(T x, int n){
    T ret = 1;
    while(n > 0) {
        if(n & 1) (ret *= x);
        (x *= x);
        n >>= 1;
    }
    return ret;
}

template <typename T>
T getReminder(T a, T b){
    if(b == 0) return -1;
    if(a >= 0 && b > 0){
        return a % b;
    } else if(a < 0 && b > 0){
        return ((a % b) + b) % b;
    } else if(a >= 0 && b < 0){
        return a % b;
    } else{
        return (abs(b) - abs(a % b)) % b;
    }
}

template<class T, class U> inline T vin(T &vec, U n) { vec.resize(n); for(int i = 0; i < (int) n; ++i) cin >> vec[i]; return vec; }
template<class T> inline void vout(T vec, string s = "\n"){ for(auto x : vec) cout << x << s; }
template<class... T> void in(T&... a){ (cin >> ... >> a); }
void out(){ cout << '\n'; }
template<class T, class... Ts> void out(const T &a, const Ts&... b){ cout << a; (cout << ... << (cout << ' ', b)); cout << '\n'; }
template<class T, class U> void inGraph(vector<vector<T>> &G, U n, U m, bool directed = false){ G.resize(n); for(int i = 0; i < m; ++i){ int a, b; cin >> a >> b; a--, b--; G[a].push_back(b); if(!directed) G[b].push_back(a); } }

template <typename T>
struct WeightedUnionFind{
    vector<int> par;
    vector<T> diff_weight;
    T ex;

    WeightedUnionFind(const int N, const T &e = 0) : par(N), diff_weight(N), ex(e){
        for(int i = 0; i < N; ++i){
            par[i] = -1;
            diff_weight[i] = e;
        }
    }

    int root(const int x){
        if(par[x] < 0){
            return x;
        }
        int px = par[x];
        int rx = root(par[x]);
        diff_weight[x] = diff_weight[x] + diff_weight[px];
        return par[x] = rx;
    }

    T weight(const int x){
        root(x);
        return diff_weight[x];
    }

    T diff(const int x, const int y){
        return weight(x) - weight(y);
    }

    void unite(const int x, const int y, const T &w){
        int tx = x, ty = y;
        T tw = w;
        int rx = root(x), ry = root(y);
        if(rx == ry) return;

        if(par[rx] < par[ry]){
            swap(rx, ry);
            swap(tx, ty);
            tw = ex - tw;
        }

        par[ry] = par[rx] + par[ry];
        par[rx] = ry;
        diff_weight[rx] = ex - diff_weight[tx] + tw + diff_weight[ty];
    }

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

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

pair<long long, vector<pair<int, int>>> shortest_path(const vector<vector<array<long long, 2>>> &G, int s, int t){
    const long long INF = 0x1fffffffffffffff;
    vector<long long> cost((int) G.size(), INF);
    vector<int> par((int) G.size(), -1);
    using P = pair<long long, long long>;
    priority_queue<P, vector<P>, greater<>> q;
    cost[s] = 0;
    par[s] = -1;
    q.emplace(0, s);

    while(q.size()){
        auto [c, at] = q.top();
        q.pop();
        if(c > cost[at]) continue;
        for(auto &[to, t] : G[at]){
            if(cost[to] > c + t){
                par[to] = at;
                cost[to] = c + t;
                q.emplace(cost[to], to);
            }
        }
    }

    if(cost[t] == INF){
        return {-1, {}};
    }
    vector<pair<int, int>> path;
    int now = t;
    while(par[now] != -1){
        path.emplace_back(par[now], now);
        now = par[now];
    }
    reverse(path.begin(), path.end());

    return {cost[t], path};
}

ll T;

void input(){
    in(T);
}

void solve(){
    ll n, m; in(n, m);
    WeightedUnionFind<ll> wuf(n);
    vector<vector<array<ll, 2>>> G(n);
    vll anse;
    ll ans = -1;
    map<P, ll> e;
    rep(i, m){
        ll u, v, w; in(u, v, w);
        u--, v--;
        if(wuf.same(u, v)){
            if(wuf.diff(u, v) == w){
                continue;
            }
            if(wuf.diff(u, v) < w) swap(u, v);
            for(auto [x, y] : shortest_path(G, u, v).second){
                anse.push_back(e[{x, y}] + 1);
            }
            anse.push_back(i + 1);
            ans = u + 1;
            out(anse.size());
            out(ans);
            out(anse);
            return;
        }else{
            wuf.unite(u, v, w);
            G[u].push_back({v, 1});
            G[v].push_back({u, 1});
            e[{u, v}] = i;
            e[{v, u}] = i;
        }
    }
    out(-1);
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout << fixed << setprecision(20);

    T = 1;
    // input();
    while(T--) solve();
}