Submission #395501

#TimeUsernameProblemLanguageResultExecution timeMemory
395501MarcoMeijerRegions (IOI09_regions)C++14
83 / 100
8032 ms46944 KiB
#include <bits/stdc++.h>
using namespace std;
 
// macros
typedef long long ll;
typedef long double ld;
typedef pair<int, int> ii;
typedef pair<ll, ll> lll;
typedef tuple<int, int, int> iii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<iii> viii;
typedef vector<ll> vll;
typedef vector<lll> vlll;
#define REP(a,b,c) for(int a=int(b); a<int(c); a++)
#define RE(a,c) REP(a,0,c)
#define RE1(a,c) REP(a,1,c+1)
#define REI(a,b,c) REP(a,b,c+1)
#define REV(a,b,c) for(int a=int(c-1); a>=int(b); a--)
#define FOR(a,b) for(auto& a : b)
#define all(a) a.begin(), a.end()
#define INF 1e18
#define EPS 1e-9
#define pb push_back
#define popb pop_back
#define fi first
#define se second
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
 
// input
template<class T> void IN(T& x) {cin >> x;}
template<class H, class... T> void IN(H& h, T&... t) {IN(h); IN(t...); }
 
// output
template<class T1, class T2> void OUT(const pair<T1,T2>& x);
template<class T> void OUT(const vector<T>& x);
template<class T> void OUT(const T& x) {cout << x;}
template<class H, class... T> void OUT(const H& h, const T&... t) {OUT(h); OUT(t...); }
template<class T1, class T2> void OUT(const pair<T1,T2>& x) {OUT(x.fi,' ',x.se);}
template<class T> void OUT(const vector<T>& x) {RE(i,x.size()) OUT(i==0?"":" ",x[i]);}
template<class... T> void OUTL(const T&... t) {OUT(t..., "\n"); }
template<class H> void OUTLS(const H& h) {OUTL(h); }
template<class H, class... T> void OUTLS(const H& h, const T&... t) {OUT(h,' '); OUTLS(t...); }
 
// dp
template<class T> bool ckmin(T&a, T&b) { bool bl = a > b; a = min(a,b); return bl;}
template<class T> bool ckmax(T&a, T&b) { bool bl = a < b; a = max(a,b); return bl;}
 
void program();
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    program();
}
 
 
//===================//
//   begin program   //
//===================//
 
const int MX = 2e5+10;
const int SQ = 450;
const int N = (1<<20);

// input
int n, r, q;
int h[MX];
vi withH[MX];

// tree
vi chl[MX];
int dfsPre[MX], treeBg[MX], treeEd[MX], curDFS=0;
void dfs(int u) {
    treeBg[u] = curDFS;
    dfsPre[u] = curDFS++;
    FOR(v,chl[u]) dfs(v);
    treeEd[u] = curDFS-1;
}

// R > 500
vi dif[MX];

// R <= 500
int m;
int ways[SQ][SQ];
int tot[MX];
int sh[MX], rh[MX];

vii regions[SQ];
void dfs2(int u, int cr, int sm) {
    if(regions[cr].empty()) regions[cr].pb({0,0});
    if(rh[h[u]] == cr)
        sm++, regions[cr].pb({treeBg[u], sm});
    FOR(v,chl[u]) dfs2(v,cr,sm);
    if(rh[h[u]] == cr)
        sm--, regions[cr].pb({treeEd[u]+1, sm});
}

void program() {
    // input
    IN(n,r,q);
    RE1(i,n) {
        if(i != 1) {
            int p; IN(p);
            chl[p].pb(i);
        }
        IN(h[i]);
    }
    dfs(1);
    RE1(i,n) withH[h[i]].pb(i);

    // R >= 500
    RE1(u,n) dif[h[u]].pb(dfsPre[u]);
    RE1(i,r) sort(all(dif[i]));

    // R <= 500
    RE1(i,n) sh[i] = i;
    sort(sh+1,sh+n+1, [](int i, int j) {
        return withH[i].size() > withH[j].size();
    });
    RE1(i,n) rh[sh[i]] = i;
    m = min(r,SQ-2);

    // fill tot
    memset(ways,0,sizeof(ways));
    RE1(j,m) {
        memset(tot,0,sizeof(tot));
        FOR(u,withH[sh[j]]) tot[u] = 1;
        REV(u,1,n+1) FOR(v,chl[u]) tot[u] += tot[v];
        RE1(i,m) FOR(u,withH[sh[i]]) ways[i][j] += tot[u];
    }

    // dfs 2
    RE1(i,m) dfs2(1,i,0);

    // answer queries
    RE(_,q) {
        int r1, r2; IN(r1,r2);
        if(rh[r1] <= m && rh[r2] <= m) {
            OUTL(ways[rh[r1]][rh[r2]]);
            cout.flush();
        } else {
            if(rh[r1] <= 300) {
                int res = 0;
                FOR(u,withH[r2]) res += (--upper_bound(all(regions[rh[r1]]),ii{dfsPre[u],1e9}))->se;
                OUTL(res);
                cout.flush();
            } else {
                int res = 0;
                FOR(u,withH[r1]) res += upper_bound(all(dif[r2]),treeEd[u]) - lower_bound(all(dif[r2]),treeBg[u]);
                OUTL(res);
                cout.flush();
            }
        }
    }
}
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