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#include "Algorithm/matroid.hpp"
#pragma once #include "Graph/bimatching.hpp" #include "Graph/dmdecomp.hpp" struct GraphicMatroid { using P = pair<int, int>; int n; vector<P> E; vector<vector<P>> G; vector<int> allow; GraphicMatroid() {} GraphicMatroid(int n, vector<P> &E) : n(n), E(E), G(n) { rep(i, 0, SZ(E)) { auto [u, v] = E[i]; G[u].push_back({v, i}); G[v].push_back({u, i}); } } void set(vector<int> &I) { allow = I; } vector<int> circuit(int e) { auto [x, y] = E[e]; vector<int> ret; ret.push_back(e); auto dfs = [&](auto &dfs, int v, int p) -> bool { if (v == y) return true; for (auto &[to, i] : G[v]) if (allow[i] and to != p) { ret.push_back(i); if (dfs(dfs, to, v)) return true; ret.pop_back(); } return false; }; if (dfs(dfs, x, -1)) return ret; else return {}; } }; struct PartitionMatroid { vector<int> grp; // -1:not assign vector<int> lim; vector<vector<int>> cnt; PartitionMatroid() {} PartitionMatroid(vector<int> &grp, vector<int> lim) : grp(grp), lim(lim) {} void set(vector<int> &I) { cnt.assign(SZ(lim), {}); rep(i, 0, SZ(grp)) if (I[i] != 0 and grp[i] != -1) { cnt[grp[i]].push_back(i); } } vector<int> circuit(int e) { if (grp[e] == -1) return {}; if (SZ(cnt[grp[e]]) + 1 > lim[grp[e]]) { vector<int> ret = cnt[grp[e]]; ret.push_back(e); return ret; } else return {}; } }; struct TransversalMatroid { using P = pair<int, int>; int n, m; vector<vector<int>> G, aug; vector<int> match, fixed; TransversalMatroid() {} TransversalMatroid(int n, int m, vector<P> &E) : n(n), m(m), G(n), aug(n), fixed(n) { for (auto &[u, v] : E) G[u].push_back(v); } void set(vector<int> &I) { vector g(n, vector<int>()); rep(e, 0, n) if (I[e]) { for (auto &to : G[e]) g[e].push_back(to); } auto match = BiMatching(n, m, g); auto dm = DMdecomposition(n, m, g, match); fixed.assign(m, 1); for (auto &v : dm.front()) if (v >= n) fixed[v - n] = 0; aug.assign(n + m, {}); rep(e, 0, n) { for (auto &to : G[e]) aug[e].push_back(to + n); } rep(i, 0, n) if (match[i] != -1) aug[match[i] + n].push_back(i); } vector<int> circuit(int e) { for (auto &to : G[e]) if (!fixed[to]) { return {}; } vector<int> used(n + m); queue<int> que; used[e] = 1; que.push(e); while (!que.empty()) { int v = que.front(); que.pop(); for (auto &to : aug[v]) if (!used[to]) { used[to] = 1; que.push(to); } } vector<int> ret; rep(i, 0, n) if (used[i]) ret.push_back(i); return ret; } }; template <typename M1, typename M2, typename Val> pair<vector<Val>, vector<vector<int>>> MinimumMatroidIntersection(M1 &m1, M2 &m2, vector<Val> &ws) { using P = pair<Val, int>; int n = SZ(ws); vector<Val> ret1; vector<vector<int>> ret2; Val profit = 0; vector<int> I(n); ret1.push_back(profit); ret2.push_back(I); for (;;) { vector G(n + 2, vector<P>()); int S = n, T = n + 1; m1.set(I); m2.set(I); rep(e, 0, n) { if (I[e]) continue; auto c1 = m1.circuit(e); if (c1.empty()) G[S].push_back({ws[e] * (n + 1) + 1, e}); else for (auto &to : c1) if (e != to) { G[to].push_back({ws[e] * (n + 1) + 1, e}); } auto c2 = m2.circuit(e); if (c2.empty()) G[e].push_back({Val(0), T}); else for (auto &to : c2) if (e != to) { G[e].push_back({-ws[to] * (n + 1) + 1, to}); } } vector<ll> dist(n + 2, INF); dist[S] = 0; vector<int> pre(n + 2, -1); for (;;) { bool upd = 0; rep(v, 0, n + 2) if (dist[v] != INF) { for (auto &[cost, to] : G[v]) { if (chmin(dist[to], dist[v] + cost)) { pre[to] = v; upd = 1; } } } if (!upd) break; } if (dist[T] == INF) break; int cur = T; while (cur != S) { cur = pre[cur]; if (cur != S) { I[cur] ^= 1; if (I[cur]) profit += ws[cur]; else profit -= ws[cur]; } } ret1.push_back(profit); ret2.push_back(I); } return {ret1, ret2}; } /** * @brief Matroid */
#line 2 "Utility/random.hpp" namespace Random { mt19937_64 randgen(chrono::steady_clock::now().time_since_epoch().count()); using u64 = unsigned long long; u64 get() { return randgen(); } template <typename T> T get(T L) { // [0,L] return get() % (L + 1); } template <typename T> T get(T L, T R) { // [L,R] return get(R - L) + L; } double uniform() { return double(get(1000000000)) / 1000000000; } string str(int n) { string ret; rep(i, 0, n) ret += get('a', 'z'); return ret; } template <typename Iter> void shuffle(Iter first, Iter last) { if (first == last) return; int len = 1; for (auto it = first + 1; it != last; it++) { len++; int j = get(0, len - 1); if (j != len - 1) iter_swap(it, first + j); } } template <typename T> vector<T> select(int n, T L, T R) { // [L,R] if (n * 2 >= R - L + 1) { vector<T> ret(R - L + 1); iota(ALL(ret), L); shuffle(ALL(ret)); ret.resize(n); return ret; } else { unordered_set<T> used; vector<T> ret; while (SZ(used) < n) { T x = get(L, R); if (!used.count(x)) { used.insert(x); ret.push_back(x); } } return ret; } } void relabel(int n, vector<pair<int, int>> &es) { shuffle(ALL(es)); vector<int> ord(n); iota(ALL(ord), 0); shuffle(ALL(ord)); for (auto &[u, v] : es) u = ord[u], v = ord[v]; } template <bool directed, bool simple> vector<pair<int, int>> genGraph(int n) { vector<pair<int, int>> cand, es; rep(u, 0, n) rep(v, 0, n) { if (simple and u == v) continue; if (!directed and u > v) continue; cand.push_back({u, v}); } int m = get(SZ(cand)); vector<int> ord; if (simple) ord = select(m, 0, SZ(cand) - 1); else { rep(_, 0, m) ord.push_back(get(SZ(cand) - 1)); } for (auto &i : ord) es.push_back(cand[i]); relabel(n, es); return es; } vector<pair<int, int>> genTree(int n) { vector<pair<int, int>> es; rep(i, 1, n) es.push_back({get(i - 1), i}); relabel(n, es); return es; } }; // namespace Random /** * @brief Random */ #line 3 "Graph/bimatching.hpp" vector<int> BiMatching(int n, int m, vector<vector<int>> &g) { rep(v, 0, n) Random::shuffle(ALL(g[v])); vector<int> L(n, -1), R(m, -1); for (;;) { vector<int> par(n, -1), root(n, -1); queue<int> que; rep(i, 0, n) if (L[i] == -1) { que.push(i); root[i] = i; } bool upd = 0; while (!que.empty()) { int v = que.front(); que.pop(); if (L[root[v]] != -1) continue; for (auto u : g[v]) { if (R[u] == -1) { while (u != -1) { R[u] = v; swap(L[v], u); v = par[v]; } upd = 1; break; } int to = R[u]; if (par[to] == -1) { root[to] = root[v]; par[to] = v; que.push(to); } } } if (!upd) break; } return L; } /** * @brief Bipartite Matching */ #line 2 "Graph/scc.hpp" struct SCC{ int n,m,cur; vector<vector<int>> g; vector<int> low,ord,id; SCC(int _n=0):n(_n),m(0),cur(0),g(_n),low(_n),ord(_n,-1),id(_n){} void resize(int _n){ n=_n; g.resize(n); low.resize(n); ord.resize(n,-1); id.resize(n); } void add_edge(int u,int v){g[u].emplace_back(v);} void dfs(int v,vector<int>& used){ ord[v]=low[v]=cur++; used.emplace_back(v); for(auto& nxt:g[v]){ if(ord[nxt]==-1){ dfs(nxt,used); chmin(low[v],low[nxt]); } else{ chmin(low[v],ord[nxt]); } } if(ord[v]==low[v]){ while(1){ int add=used.back(); used.pop_back(); ord[add]=n; id[add]=m; if(v==add)break; } m++; } } void run(){ vector<int> used; rep(v,0,n)if(ord[v]==-1)dfs(v,used); for(auto& x:id)x=m-1-x; } }; /** * @brief Strongly Connected Components */ #line 4 "Graph/dmdecomp.hpp" vector<vector<int>> DMdecomposition(int n, int m, vector<vector<int>> &g, vector<int> match) { if (match.empty()) match = BiMatching(n, m, g); vector G(n + m, vector<int>()), REV(n + m, vector<int>()); rep(i, 0, n) for (auto &j : g[i]) { G[i].push_back(j + n); REV[j + n].push_back(i); } vector<int> R(m, -1); rep(i, 0, n) if (match[i] != -1) { G[match[i] + n].push_back(i); REV[i].push_back(match[i] + n); R[match[i]] = i; } vector<int> V0, Vinf; queue<int> que; vector<int> used(n + m); rep(i, 0, n) if (match[i] == -1) { used[i] = 1; que.push(i); } while (!que.empty()) { int v = que.front(); que.pop(); Vinf.push_back(v); for (auto &to : G[v]) if (!used[to]) { used[to] = 1; que.push(to); } } rep(i, 0, m) if (R[i] == -1) { used[i + n] = 1; que.push(i + n); } while (!que.empty()) { int v = que.front(); que.pop(); V0.push_back(v); for (auto &to : REV[v]) if (!used[to]) { used[to] = 1; que.push(to); } } SCC scc(n + m); rep(i, 0, n + m) for (auto &to : G[i]) { if (!used[i] and !used[to]) scc.add_edge(i, to); } scc.run(); vector group(scc.m, vector<int>()); rep(i, 0, n + m) if (!used[i]) group[scc.id[i]].push_back(i); vector<vector<int>> ret; ret.push_back(V0); for (auto &v : group) ret.push_back(v); ret.push_back(Vinf); return ret; } /** * @brief DM decomposition */ #line 4 "Algorithm/matroid.hpp" struct GraphicMatroid { using P = pair<int, int>; int n; vector<P> E; vector<vector<P>> G; vector<int> allow; GraphicMatroid() {} GraphicMatroid(int n, vector<P> &E) : n(n), E(E), G(n) { rep(i, 0, SZ(E)) { auto [u, v] = E[i]; G[u].push_back({v, i}); G[v].push_back({u, i}); } } void set(vector<int> &I) { allow = I; } vector<int> circuit(int e) { auto [x, y] = E[e]; vector<int> ret; ret.push_back(e); auto dfs = [&](auto &dfs, int v, int p) -> bool { if (v == y) return true; for (auto &[to, i] : G[v]) if (allow[i] and to != p) { ret.push_back(i); if (dfs(dfs, to, v)) return true; ret.pop_back(); } return false; }; if (dfs(dfs, x, -1)) return ret; else return {}; } }; struct PartitionMatroid { vector<int> grp; // -1:not assign vector<int> lim; vector<vector<int>> cnt; PartitionMatroid() {} PartitionMatroid(vector<int> &grp, vector<int> lim) : grp(grp), lim(lim) {} void set(vector<int> &I) { cnt.assign(SZ(lim), {}); rep(i, 0, SZ(grp)) if (I[i] != 0 and grp[i] != -1) { cnt[grp[i]].push_back(i); } } vector<int> circuit(int e) { if (grp[e] == -1) return {}; if (SZ(cnt[grp[e]]) + 1 > lim[grp[e]]) { vector<int> ret = cnt[grp[e]]; ret.push_back(e); return ret; } else return {}; } }; struct TransversalMatroid { using P = pair<int, int>; int n, m; vector<vector<int>> G, aug; vector<int> match, fixed; TransversalMatroid() {} TransversalMatroid(int n, int m, vector<P> &E) : n(n), m(m), G(n), aug(n), fixed(n) { for (auto &[u, v] : E) G[u].push_back(v); } void set(vector<int> &I) { vector g(n, vector<int>()); rep(e, 0, n) if (I[e]) { for (auto &to : G[e]) g[e].push_back(to); } auto match = BiMatching(n, m, g); auto dm = DMdecomposition(n, m, g, match); fixed.assign(m, 1); for (auto &v : dm.front()) if (v >= n) fixed[v - n] = 0; aug.assign(n + m, {}); rep(e, 0, n) { for (auto &to : G[e]) aug[e].push_back(to + n); } rep(i, 0, n) if (match[i] != -1) aug[match[i] + n].push_back(i); } vector<int> circuit(int e) { for (auto &to : G[e]) if (!fixed[to]) { return {}; } vector<int> used(n + m); queue<int> que; used[e] = 1; que.push(e); while (!que.empty()) { int v = que.front(); que.pop(); for (auto &to : aug[v]) if (!used[to]) { used[to] = 1; que.push(to); } } vector<int> ret; rep(i, 0, n) if (used[i]) ret.push_back(i); return ret; } }; template <typename M1, typename M2, typename Val> pair<vector<Val>, vector<vector<int>>> MinimumMatroidIntersection(M1 &m1, M2 &m2, vector<Val> &ws) { using P = pair<Val, int>; int n = SZ(ws); vector<Val> ret1; vector<vector<int>> ret2; Val profit = 0; vector<int> I(n); ret1.push_back(profit); ret2.push_back(I); for (;;) { vector G(n + 2, vector<P>()); int S = n, T = n + 1; m1.set(I); m2.set(I); rep(e, 0, n) { if (I[e]) continue; auto c1 = m1.circuit(e); if (c1.empty()) G[S].push_back({ws[e] * (n + 1) + 1, e}); else for (auto &to : c1) if (e != to) { G[to].push_back({ws[e] * (n + 1) + 1, e}); } auto c2 = m2.circuit(e); if (c2.empty()) G[e].push_back({Val(0), T}); else for (auto &to : c2) if (e != to) { G[e].push_back({-ws[to] * (n + 1) + 1, to}); } } vector<ll> dist(n + 2, INF); dist[S] = 0; vector<int> pre(n + 2, -1); for (;;) { bool upd = 0; rep(v, 0, n + 2) if (dist[v] != INF) { for (auto &[cost, to] : G[v]) { if (chmin(dist[to], dist[v] + cost)) { pre[to] = v; upd = 1; } } } if (!upd) break; } if (dist[T] == INF) break; int cur = T; while (cur != S) { cur = pre[cur]; if (cur != S) { I[cur] ^= 1; if (I[cur]) profit += ws[cur]; else profit -= ws[cur]; } } ret1.push_back(profit); ret2.push_back(I); } return {ret1, ret2}; } /** * @brief Matroid */