제출 #333447

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
333447		rqi	조이터에서 친구를 만드는건 재밌어 (JOI20_joitter2)	C++14	100 / 100	601 ms	61560 KiB

joitter2

#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); }
      |                      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 1 / 1
• Subtask 2: 16 / 16
• Subtask 3: 83 / 83