Submission #146028

#	Time	Username	Problem	Language	Result	Execution time	Memory
146028		popovicirobert	Regions (IOI09_regions)	C++14	65 / 100	8076 ms	104876 KiB

regions

#include <bits/stdc++.h>
#define lsb(x) (x & (-x))
#define ll long long
#define ull unsigned long long


#if 0
const int MOD = ;

inline int lgput(int a, int b) {
    int ans = 1;
    while(b > 0) {
        if(b & 1) ans = (1LL * ans * a) % MOD;
        b >>= 1;
        a = (1LL * a * a) % MOD;
    }
    return ans;
}

inline void mod(int &x) {
    if(x >= MOD)
        x -= MOD;
}

inline void add(int &x, int y) {
    x += y;
    mod(x);
}

inline void sub(int &x, int y) {
    x += MOD - y;
    mod(x);
}

inline void mul(int &x, int y) {
    x = (1LL * x * y) % MOD;
}

inline int inv(int x) {
    return lgput(x, MOD - 2);
}
#endif

#if 0
int fact[], invfact[];

inline void prec(int n) {
    fact[0] = 1;
    for(int i = 1; i <= n; i++) {
        fact[i] = (1LL * fact[i - 1] * i) % MOD;
    }
    invfact[n] = lgput(fact[n], MOD - 2);
    for(int i = n - 1; i >= 0; i--) {
        invfact[i] = (1LL * invfact[i + 1] * (i + 1)) % MOD;
    }
}

inline int comb(int n, int k) {
    if(n < k) return 0;
    return (1LL * fact[n] * (1LL * invfact[k] * invfact[n - k] % MOD)) % MOD;
}
#endif

using namespace std;

const int MAXN = (int) 2e5;
const int MAXR = 25000;
const int B = 500;

vector <int> g[MAXN + 1];
int id[MAXN + 1], fr[MAXR + 1];

vector <int> pos[MAXR + 1], nodes[MAXR + 1];
int idl[MAXN + 1], idr[MAXN + 1], sz;

void dfs(int nod) {
    idl[nod] = ++sz;
    nodes[id[nod]].push_back(nod);
    pos[id[nod]].push_back(sz);
    for(auto it : g[nod]) {
        dfs(it);
    }
    idr[nod] = sz;
}

int where[MAXR + 1], vals[MAXN + 1];
ll cnt[MAXR + 1][MAXN / B];

void dfs1(int nod, int num) {
    for(int i = 0; i < num; i++) {
        cnt[id[nod]][i] += fr[vals[i]];
    }
    fr[id[nod]]++;
    for(auto it : g[nod]) {
        dfs1(it, num);
    }
    fr[id[nod]]--;
}

int main() {
#if 0
    ifstream cin("A.in");
    ofstream cout("A.out");
#endif
    int i, n, r, q;
    ios::sync_with_stdio(false);
    cin.tie(0), cout.tie(0);

    cin >> n >> r >> q;
    cin >> id[1];
    for(i = 2; i <= n; i++) {
        int par;
        cin >> par >> id[i];
        g[par].push_back(i);
    }
    for(i = 1; i <= n; i++) {
        fr[id[i]]++;
    }
    dfs(1);

    int num = 0;
    for(i = 1; i <= r; i++) {
        if(fr[i] >= B) {
            vals[num] = i;
            where[i] = num++;
        }
    }

    fill(fr, fr + MAXR + 1, 0);
    dfs1(1, num);

    while(q--) {
        int r1, r2;
        cin >> r1 >> r2;
        ll ans = 0;
        if(fr[r1] < B) {
            for(auto nod : nodes[r1]) {
                ans += upper_bound(pos[r2].begin(), pos[r2].end(), idr[nod]) - lower_bound(pos[r2].begin(), pos[r2].end(), idl[nod] + 1);
            }
        }
        else {
            ans = cnt[r2][where[r1]];
        }
        cout << ans << "\n";
        cout.flush();
    }

    return 0;
}

• Subtask 1: 15 / 15
• Subtask 2: 50 / 85