제출 #333447

#제출 시각아이디문제언어결과실행 시간메모리
333447rqi조이터에서 친구를 만드는건 재밌어 (JOI20_joitter2)C++14
100 / 100
601 ms61560 KiB
#include <bits/stdc++.h> using namespace std; typedef long long ll; typedef long double ld; typedef double db; typedef string str; typedef pair<int,int> pi; typedef pair<ll,ll> pl; typedef pair<db,db> pd; typedef vector<int> vi; typedef vector<bool> vb; typedef vector<ll> vl; typedef vector<db> vd; typedef vector<str> vs; typedef vector<pi> vpi; typedef vector<pl> vpl; typedef vector<pd> vpd; #define mp make_pair #define f first #define s second #define sz(x) (int)(x).size() #define all(x) begin(x), end(x) #define rall(x) (x).rbegin(), (x).rend() #define sor(x) sort(all(x)) #define rsz resize #define ins insert #define ft front() #define bk back() #define pf push_front #define pb push_back #define eb emplace_back #define lb lower_bound #define ub upper_bound #define FOR(i,a,b) for (int i = (a); i < (b); ++i) #define F0R(i,a) FOR(i,0,a) #define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i) #define R0F(i,a) ROF(i,0,a) #define trav(a,x) for (auto& a: x) const int MOD = 1e9+7; // 998244353; const int MX = 2e5+5; const ll INF = 1e18; const ld PI = acos((ld)-1); const int xd[4] = {1,0,-1,0}, yd[4] = {0,1,0,-1}; mt19937 rng((uint32_t)chrono::steady_clock::now().time_since_epoch().count()); template<class T> bool ckmin(T& a, const T& b) { return b < a ? a = b, 1 : 0; } template<class T> bool ckmax(T& a, const T& b) { return a < b ? a = b, 1 : 0; } constexpr int pct(int x) { return __builtin_popcount(x); } constexpr int bits(int x) { return 31-__builtin_clz(x); } // floor(log2(x)) ll cdiv(ll a, ll b) { return a/b+((a^b)>0&&a%b); } // divide a by b rounded up ll fdiv(ll a, ll b) { return a/b-((a^b)<0&&a%b); } // divide a by b rounded down ll half(ll x) { return fdiv(x,2); } template<class T, class U> T fstTrue(T lo, T hi, U f) { // note: if (lo+hi)/2 is used instead of half(lo+hi) then this will loop infinitely when lo=hi hi ++; assert(lo <= hi); // assuming f is increasing while (lo < hi) { // find first index such that f is true T mid = half(lo+hi); f(mid) ? hi = mid : lo = mid+1; } return lo; } template<class T, class U> T lstTrue(T lo, T hi, U f) { lo --; assert(lo <= hi); // assuming f is decreasing while (lo < hi) { // find first index such that f is true T mid = half(lo+hi+1); f(mid) ? lo = mid : hi = mid-1; } return lo; } template<class T> void remDup(vector<T>& v) { sort(all(v)); v.erase(unique(all(v)),end(v)); } // INPUT template<class A> void re(complex<A>& c); template<class A, class B> void re(pair<A,B>& p); template<class A> void re(vector<A>& v); template<class A, size_t SZ> void re(array<A,SZ>& a); template<class T> void re(T& x) { cin >> x; } void re(db& d) { str t; re(t); d = stod(t); } void re(ld& d) { str t; re(t); d = stold(t); } template<class H, class... T> void re(H& h, T&... t) { re(h); re(t...); } template<class A> void re(complex<A>& c) { A a,b; re(a,b); c = {a,b}; } template<class A, class B> void re(pair<A,B>& p) { re(p.f,p.s); } template<class A> void re(vector<A>& x) { trav(a,x) re(a); } template<class A, size_t SZ> void re(array<A,SZ>& x) { trav(a,x) re(a); } // TO_STRING #define ts to_string str ts(char c) { return str(1,c); } str ts(const char* s) { return (str)s; } str ts(str s) { return s; } str ts(bool b) { #ifdef LOCAL return b ? "true" : "false"; #else return ts((int)b); #endif } template<class A> str ts(complex<A> c) { stringstream ss; ss << c; return ss.str(); } str ts(vector<bool> v) { str res = "{"; F0R(i,sz(v)) res += char('0'+v[i]); res += "}"; return res; } template<size_t SZ> str ts(bitset<SZ> b) { str res = ""; F0R(i,SZ) res += char('0'+b[i]); return res; } template<class A, class B> str ts(pair<A,B> p); template<class T> str ts(T v) { // containers with begin(), end() #ifdef LOCAL bool fst = 1; str res = "{"; for (const auto& x: v) { if (!fst) res += ", "; fst = 0; res += ts(x); } res += "}"; return res; #else bool fst = 1; str res = ""; for (const auto& x: v) { if (!fst) res += " "; fst = 0; res += ts(x); } return res; #endif } template<class A, class B> str ts(pair<A,B> p) { #ifdef LOCAL return "("+ts(p.f)+", "+ts(p.s)+")"; #else return ts(p.f)+" "+ts(p.s); #endif } // OUTPUT template<class A> void pr(A x) { cout << ts(x); } template<class H, class... T> void pr(const H& h, const T&... t) { pr(h); pr(t...); } void ps() { pr("\n"); } // print w/ spaces template<class H, class... T> void ps(const H& h, const T&... t) { pr(h); if (sizeof...(t)) pr(" "); ps(t...); } // DEBUG void DBG() { cerr << "]" << endl; } template<class H, class... T> void DBG(H h, T... t) { cerr << ts(h); if (sizeof...(t)) cerr << ", "; DBG(t...); } #ifdef LOCAL // compile with -DLOCAL, chk -> fake assert #define dbg(...) cerr << "Line(" << __LINE__ << ") -> [" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__) #define chk(...) if (!(__VA_ARGS__)) cerr << "Line(" << __LINE__ << ") -> function(" \ << __FUNCTION__ << ") -> CHK FAILED: (" << #__VA_ARGS__ << ")" << "\n", exit(0); #else #define dbg(...) 0 #define chk(...) 0 #endif // FILE I/O void setIn(str s) { freopen(s.c_str(),"r",stdin); } void setOut(str s) { freopen(s.c_str(),"w",stdout); } void unsyncIO() { cin.tie(0)->sync_with_stdio(0); } void setIO(str s = "") { unsyncIO(); // cin.exceptions(cin.failbit); // throws exception when do smth illegal // ex. try to read letter into int if (sz(s)) { setIn(s+".in"), setOut(s+".out"); } // for USACO } /** * Description: Hash map with the same API as unordered\_map, but \tilde 3x faster. * Initial capacity must be a power of 2 if provided. * Source: KACTL * Usage: ht<int,int> h({},{},{},{},{1<<16}); */ #include <ext/pb_ds/assoc_container.hpp> using namespace __gnu_pbds; struct chash { /// use most bits rather than just the lowest ones const uint64_t C = ll(2e18*PI)+71; // large odd number const int RANDOM = rng(); ll operator()(ll x) const { /// https://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html return __builtin_bswap64((x^RANDOM)*C); } }; template<class K,class V> using um = unordered_map<K,V,chash>; template<class K,class V> using ht = gp_hash_table<K,V,chash>; template<class K,class V> V get(ht<K,V>& u, K x) { auto it = u.find(x); return it == end(u) ? 0 : it->s; } template<class K,class V> void ERASE(ht<K,V>& u, K x) { if(u.find(x) != u.end()) u.erase(x); } ll toll(int a, int b){ return ll(100005)*ll(a)+ll(b); } const int mx = 100005; int N, M; int A[300005]; int B[300005]; ll ans; int indeg[mx]; vpi elist; vector<bool> inactive; vi grpeds[mx]; //includes inactive edges ht<ll, null_type> ntog; ht<ll, null_type> gtog; queue<pi> mergers; /** * Description: Disjoint Set Union with path compression * and union by size. Add edges and test connectivity. * Use for Kruskal's or Boruvka's minimum spanning tree. * Time: O(\alpha(N)) * Source: CSAcademy, KACTL * Verification: * */ struct DSU { vi e; void init(int N) { e = vi(N,-1); } int get(int x) { return e[x] < 0 ? x : e[x] = get(e[x]); } bool sameSet(int a, int b) { return get(a) == get(b); } int size(int x) { return -e[get(x)]; } void merge(int X, int Y){ X = get(X); Y = get(Y); if(X == Y) return; if(sz(grpeds[Y]) > sz(grpeds[X])){ swap(X, Y); } //dbg(X, Y); for(auto u: grpeds[Y]){ if(inactive[u]) continue; if(get(elist[u].f) == X){ ans-=size(Y); indeg[Y]--; inactive[u] = 1; //ntog.erase(toll(elist[u].f, elist[u].s)); ERASE(ntog, toll(elist[u].f, elist[u].s)); } else if(elist[u].s == X){ ans-=size(X); indeg[X]--; inactive[u] = 1; //ntog.erase(toll(elist[u].f, elist[u].s)); ERASE(ntog, toll(elist[u].f, elist[u].s)); } } ERASE(gtog, toll(X, Y)); ERASE(gtog, toll(Y, X)); ans-=ll(size(X))*ll(size(X)-1); ans-=ll(size(Y))*ll(size(Y)-1); ans+=ll(size(X)+size(Y))*ll(size(X)+size(Y)-1); for(auto u: grpeds[Y]){ if(inactive[u]) continue; if(get(elist[u].f) == Y){ //out edge grpeds[X].pb(u); ERASE(gtog, toll(Y, elist[u].s)); gtog.ins(toll(X, elist[u].s)); } else{ //in edge int a = elist[u].f; if(ntog.find(toll(a, X)) != ntog.end()){ //edge already exists ans-=size(Y); indeg[Y]--; inactive[u] = 1; //ntog.erase(toll(elist[u].f, elist[u].s)); ERASE(ntog, toll(elist[u].f, elist[u].s)); ERASE(gtog, toll(get(a), Y)); } else{ //remove and add edge ans-=size(Y); ans+=size(X); indeg[Y]--; indeg[X]++; elist[u].s = X; grpeds[X].pb(u); //ntog.erase(toll(elist[u].f, Y)); ERASE(ntog, toll(elist[u].f, Y)); ntog.ins(toll(elist[u].f, X)); ERASE(gtog, toll(get(a), Y)); gtog.ins(toll(get(a), X)); } } } ans+=ll(size(Y))*ll(indeg[X]); e[X] += e[Y]; e[Y] = X; for(auto u: grpeds[Y]){ if(inactive[u]) continue; int A = get(elist[u].f); int B = get(elist[u].s); assert(A != B); if(gtog.find(toll(A, B)) != gtog.end() && gtog.find(toll(B, A)) != gtog.end()){ mergers.push(mp(A, B)); } } grpeds[Y].clear(); } bool unite(int x, int y) { // union by size int X = get(x); int Y = get(y); if (X == Y) return 0; if(ntog.find(toll(x, Y)) != ntog.end()) return 0; if(gtog.find(toll(Y, X)) == gtog.end()){ ans+=size(Y); indeg[Y]++; int eind = sz(elist); elist.pb(mp(x, Y)); inactive.pb(0); grpeds[X].pb(eind); grpeds[Y].pb(eind); ntog.ins(toll(x, Y)); gtog.ins(toll(X, Y)); return 1; } //MERGE mergers.push(mp(X, Y)); return 1; } }; /**template<class T> T kruskal(int N, vector<pair<T,pi>> ed) { sort(all(ed)); T ans = 0; DSU D; D.init(N); // edges that unite are in MST trav(a,ed) if (D.unite(a.s.f,a.s.s)) ans += a.f; return ans; }*/ DSU dsu; int main() { setIO(); int N, M; cin >> N >> M; for(int i = 1; i <= M; i++){ cin >> A[i] >> B[i]; } dsu.init(N+5); for(int i = 1; i <= M; i++){ dsu.unite(A[i], B[i]); while(sz(mergers)){ pi a = mergers.front(); mergers.pop(); dsu.merge(a.f, a.s); } ps(ans); } // you should actually read the stuff at the bottom } /* stuff you should look for * int overflow, array bounds * special cases (n=1?) * do smth instead of nothing and stay organized * WRITE STUFF DOWN */

컴파일 시 표준 에러 (stderr) 메시지

joitter2.cpp: In function 'void setIn(str)':
joitter2.cpp:168:28: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
  168 | void setIn(str s) { freopen(s.c_str(),"r",stdin); }
      |                     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
joitter2.cpp: In function 'void setOut(str)':
joitter2.cpp:169:29: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
  169 | void setOut(str s) { freopen(s.c_str(),"w",stdout); }
      |                      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
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