Submission #409055

#	Time	Username	Problem	Language	Result	Execution time	Memory
409055		balbit	Inside information (BOI21_servers)	C++14	50 / 100	510 ms	56612 KiB

servers

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define y1 zck_is_king
#define pii pair<int, int>
#define ull unsigned ll
#define f first
#define s second
#define ALL(x) x.begin(),x.end()
#define SZ(x) (int)x.size()
#define SQ(x) (x)*(x)
#define MN(a,b) a = min(a,(__typeof__(a))(b))
#define MX(a,b) a = max(a,(__typeof__(a))(b))
#define pb push_back
#define REP(i,n) for (int i = 0; i<n; ++i)
#define RREP(i,n) for (int i = n-1; i>=0; --i)
#define REP1(i,n) for (int i = 1; i<=n; ++i)
#define SORT_UNIQUE(c) (sort(c.begin(),c.end()), c.resize(distance(c.begin(),unique(c.begin(),c.end()))))
#ifdef BALBIT
#define IOS()
#define bug(...) fprintf(stderr,"#%d (%s) = ",__LINE__,#__VA_ARGS__),_do(__VA_ARGS__);
template<typename T> void _do(T &&x){cerr<<x<<endl;}
template<typename T, typename ...S> void _do(T &&x, S &&...y){cerr<<x<<", ";_do(y...);}
#else
#define IOS() ios_base::sync_with_stdio(0);cin.tie(0);
#define endl '\n'
#define bug(...)
#endif

const int iinf = 1e9+10;
const ll inf = 1ll<<60;
const ll mod = 1e9+7 ;


void GG(){cout<<"0\n"; exit(0);}

ll mpow(ll a, ll n, ll mo = mod){ // a^n % mod
    ll re=1;
    while (n>0){
        if (n&1) re = re*a %mo;
        a = a*a %mo;
        n>>=1;
    }
    return re;
}

ll inv (ll b, ll mo = mod){
    if (b==1) return b;
    return (mo-mo/b) * inv(mo%b,mo) % mo;
}

const int maxn = 240000+5;

struct edge{
    int u, t;
};
vector<edge> g[maxn];
vector<int> cnt[maxn];
//vector<int> frm[maxn];

int now[maxn];
int ans[maxn*2];
vector<int> hey[maxn];
vector<int> hey2[maxn];
struct havequery{
    int a,b,t;
};

int inc[maxn], decr[maxn];
int par[maxn], parw[maxn]; // parent and parent weight
int fa[21][maxn];
int dep[maxn];
int L[maxn], R[maxn];
int IT = 0;
bool ispar(int a, int b) {
    return L[a] <= L[b] && R[a] >= R[b];
}
void dfs(int v, int p) {
    L[v] =R[v]=IT++;
    for (edge e : g[v]) {
        int u = e.u;
        if (u != p) {
            fa[0][u] = v;
            par[u] = v; parw[u] = e.t;
            dep[u] = dep[v] + 1;
            inc[u] = decr[u] = v;
            if (parw[u] > parw[v]) {
                inc[u] = inc[v];
            }
            else{
                decr[u] = decr[v];
            }
            if (v != 0) {
                assert(parw[u] != parw[v]);
            }
            dfs(u,v);
            R[v] = R[u];
        }
    }
}

int kth(int a, int k) {
    for (int j = 0; j<=20; ++j) {
        if (k & (1<<j)) a = fa[j][a];
    }
    return a;
}

pii LCA(int a, int b) {
    bool swp = 0;
    if (dep[a] < dep[b]) {
        swap(a,b); swp = 1;
    }
    a = kth(a, dep[a] - dep[b]);
    if (a == b) return {a,b};
    assert(dep[a] == dep[b]);
    for (int j = 20; j>=0; --j) {
        if (fa[j][a] != fa[j][b]) {
            a = fa[j][a]; b = fa[j][b];
        }
    }
    assert(a!=b);
    if (swp) swap(a,b);
    return {a,b};
}


bool yes(havequery HH){
    int a = HH.a, b = HH.b;
    swap(a,b); // walking from a to b!!!!!

    pii lol = LCA(a,b);
    int A = lol.f, B = lol.s;
    int C = A==B?A:par[A];
//    if (A!=B) assert(par[A] == par[B]);

    if (dep[inc[b]] > dep[C] || dep[decr[a]] > dep[C]) {
        return 0;
    }

    if (A!=B) {
        if (parw[A] > parw[B]) {
            return 0;
        }
    }

    int hoho = HH.t;
    if (a == b) {
        return 1;
    }
    int lstedge;

    if (C == b) {
        int thon = kth(a, dep[a] - dep[C] - 1);
        assert(par[thon] == C);
        lstedge = parw[thon];
    }else{
        lstedge = parw[b];
    }
    if (lstedge > HH.t) {
        return 0;
    }

    return 1;
}

int pa[maxn], pb[maxn];
bool isedge[maxn];

signed main(){
    IOS();
    int n,q; cin>>n>>q; q += n-1;
    vector<havequery> hv;
//    fill(ans, ans+maxn, 20202930);
    vector<pair<pii, int> > E;
//    REP(i,n) here[i].pb(i), nof[i] = 1;
    vector<pii> hmm;
    REP(i,q) {
        char c; cin>>c;
        if (c == 'S') {
            int a,b; cin>>a>>b; --a; --b;
            pa[i] = a; pb[i] =b; isedge[i] = 1;
            g[a].pb({b,i});
            g[b].pb({a,i});
            E.pb({{a,b},i});
            ans[i] = 202022020;

        }
        if (c == 'Q') {
            int a, b; cin>>a>>b; --a; --b;
            hv.pb({a,b,i});

        }
        if (c == 'C') {
            int a; cin>>a; --a;
//            ans[i] = nof[a];
            hey[a].pb(i);
            hey2[a].pb(i);
            hmm.pb({a,i});
        }
    }
    dfs(0, -1);
    REP1(j, 20) REP(i,n) fa[j][i] = fa[j-1][fa[j-1][i]];
    reverse(ALL(E));
    fill(now, now+maxn, 1);
    const int BS = 6000;
    int start = 0; while (start + BS<=q) start += BS;
    bug(start);
    for (int T = start; T >=0; T-=BS){

        fill(now, now+maxn, 1);
        for( auto P : E) {
            if (P.s >= T) continue;
            int a = P.f.f, b=P.f.s;
            int tm = P.s;
            bug(a,b,tm);
            for (int v : {a,b}) {
                while (!hey[v].empty()) {
                    if (hey[v].back() >= T-1) {
                        ans[hey[v].back()] -= now[v];
                        hey[v].pop_back();
                    }else break;
                }
            }
            int nw = now[a] + now[b];
            now[a] = now[b] = nw;
        }
        REP(i,n) {
            while (!hey[i].empty() ) {
                if (hey[i].back() >= T-1) {
                    ans[hey[i].back()] -= now[i];
                    hey[i].pop_back();
                }else break;
            }
        }

    }
    REP(i,n) {
        for (int tt : hey2[i]) ans[tt] += 1 + now[i];
    }

    {
        for (havequery HH : hv) {
//            continue;
            ans[HH.t] = yes(HH)?-1:-2;
            // is the path from a
        }
    }
    for (pii p : hmm) {
        int v = p.f; int ansi = p.s;
        int tk = 0;
        while (tk -1 <= ansi) tk += BS;
        tk -= BS;
        for (int i = tk; i <= ansi; ++i) {
            bug(i, ansi);
            if (!isedge[i]) continue;
            int a = pa[i], b= pb[i];
            if (dep[a] > dep[b]) swap(a,b);
            if (ispar(b,v)) {
                swap(a,b);
            }
            // i want b!
            ans[ansi] += yes({b,v,ansi});
        }
    }
    int nnn = 0;
    REP(i,q) {
        assert(ans[i] != 0);
        if (ans[i] < 10000000) {
            ++nnn;
            if (ans[i] > 0) cout<<ans[i]<<endl;
            else cout<<(ans[i] == -1?"yes":"no")<<endl;
        }
    }
    assert(nnn == (q-n+1));

}

/*
6 16
S 3 4
Q 3 4
Q 4 3
C 1
C 2
Q 2 4
Q 4 2
S 2 6
C 2
C 4
S 1 2
S 2 3
C 3
Q 5 4
S 2 5
Q 5 4
Q 2 4
C 4
C 3
Q 1 4
C 5
*/

Compilation message (stderr)

servers.cpp: In function 'bool yes(havequery)':
servers.cpp:147:9: warning: unused variable 'hoho' [-Wunused-variable]
  147 |     int hoho = HH.t;
      |         ^~~~
servers.cpp: In function 'int main()':
servers.cpp:215:17: warning: unused variable 'tm' [-Wunused-variable]
  215 |             int tm = P.s;
      |                 ^~

• Subtask 1: 2.5 / 2.5
• Subtask 2: 0 / 2.5
• Subtask 3: 2.5 / 2.5
• Subtask 4: 0 / 2.5
• Subtask 5: 5 / 5
• Subtask 6: 0 / 5
• Subtask 7: 10 / 10
• Subtask 8: 0 / 10
• Subtask 9: 12.5 / 12.5
• Subtask 10: 0 / 12.5
• Subtask 11: 17.5 / 17.5
• Subtask 12: 0 / 17.5