Submission #311374

#	Time	Username	Problem	Language	Result	Execution time	Memory
311374		caoash	Regions (IOI09_regions)	C++14	55 / 100	7578 ms	131072 KiB

regions

#include <bits/stdc++.h> 
using namespace std;

using ll = long long;

using vi = vector<int>;
using vl = vector<ll>;
#define pb push_back
#define rsz resize
#define all(x) begin(x), end(x)
#define sz(x) (int)(x).size()

using pi = pair<int,int>;
#define f first
#define s second
#define mp make_pair

const int MX = 200005;
const int MOD = (int) (1e9 + 7);
const ll INF = (ll) 1e18;

namespace output {
  void pr(int x) {
    cout << x;
  }
  void pr(long x) {
    cout << x;
  }
  void pr(ll x) {
    cout << x;
  }
  void pr(unsigned x) {
    cout << x;
  }
  void pr(unsigned long x) {
    cout << x;
  }
  void pr(unsigned long long x) {
    cout << x;
  }
  void pr(float x) {
    cout << x;
  }
  void pr(double x) {
    cout << x;
  }
  void pr(long double x) {
    cout << x;
  }
  void pr(char x) {
    cout << x;
  }
  void pr(const char * x) {
    cout << x;
  }
  void pr(const string & x) {
    cout << x;
  }
  void pr(bool x) {
    pr(x ? "true" : "false");
  }

  template < class T1, class T2 > void pr(const pair < T1, T2 > & x);
  template < class T > void pr(const T & x);

  template < class T, class...Ts > void pr(const T & t,
    const Ts & ...ts) {
    pr(t);
    pr(ts...);
  }
  template < class T1, class T2 > void pr(const pair < T1, T2 > & x) {
    pr("{", x.f, ", ", x.s, "}");
  }
  template < class T > void pr(const T & x) {
    pr("{"); // const iterator needed for vector<bool>
    bool fst = 1;
    for (const auto & a: x) pr(!fst ? ", " : "", a), fst = 0;
    pr("}");
  }

  void ps() {
    pr("\n");
  } // print w/ spaces
  template < class T, class...Ts > void ps(const T & t,
    const Ts & ...ts) {
    pr(t);
    if (sizeof...(ts)) pr(" ");
    ps(ts...);
  }

  void pc() {
    cout << "]" << endl;
  } // debug w/ commas
  template < class T, class...Ts > void pc(const T & t,
    const Ts & ...ts) {
    pr(t);
    if (sizeof...(ts)) pr(", ");
    pc(ts...);
  }
  #define dbg(x...) pr("[", #x, "] = ["), pc(x);
}

#ifdef LOCAL
using namespace output;
#endif

template <class T, int ...Ns> struct BIT {
	T val = 0; void upd(T v) { val += v; }
	T query() { return val; }
};
template <class T, int N, int... Ns> struct BIT<T, N, Ns...> {
	BIT<T,Ns...> bit[N+1];
	template<typename... Args> void upd(int pos, Args... args) { assert(pos > 0);
		for (; pos<=N; pos+=pos&-pos) bit[pos].upd(args...); }
	template<typename... Args> T sum(int r, Args... args) {
		T res=0; for (;r;r-=r&-r) res += bit[r].query(args...); 
		return res; }
	template<typename... Args> T query(int l, int r, Args... 
		args) { return sum(r,args...)-sum(l-1,args...); }
}; 

const int B = 500;
const int MXR = 25005;

vi adj[MX];
int nr[MX], p[MX], good[MXR], st[MX], sz[MX];
int cnt = 0;
BIT<int, MX> orz;
vi locs[MXR];
map<int, int> vals[MX];
map<pi, int> pre;

void dfs_init(int v, int p) {
    st[v] = cnt++;
    sz[v] = 1;
    for (int to : adj[v]) {
        if (to != p) {
            dfs_init(to, v);
            sz[v] += sz[to];
        }
    }
}

void comb(map<int, int> &a, map<int, int> &b) {
    if (sz(a) < sz(b)) swap(a, b);
    for (auto x : b) a.insert(x);
    b.clear();
}

void dfs_merge(int v, int p) {
    if (good[nr[v]]) vals[v][nr[v]]++;
    for (int to : adj[v]) {
        if (to != p) {
            dfs_merge(to, v);
            comb(vals[v], vals[to]);
        }
    }
    assert(sz(vals[v]) <= B);
    if (!good[nr[v]]) {
        for (auto x : vals[v]) {
            pre[mp(nr[v], x.f)] += x.s;
        }
    }
}

void dfs_path(int v, int p, map<int, int> &curr) {
    assert(sz(curr) <= B);
    for (auto x : curr) {
        pre[mp(x.f, nr[v])] += x.s;
    }
    for (int to : adj[v]) {
        if (to != p) {
            if (good[nr[to]]) curr[nr[to]]++;
            dfs_path(to, v, curr);
            if (good[nr[to]]) curr[nr[to]]--;
        }
    }
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n, r, q; cin >> n >> r >> q;
    for (int i = 0; i < n; i++) {
        if (i) {
            cin >> p[i];
            p[i]--;
        }
        cin >> nr[i];
        nr[i]--;
        good[nr[i]]++;
        locs[nr[i]].pb(i);
    }
    for (int i = 1; i < n; i++) {
        adj[p[i]].pb(i);
    }
    for (int i = 0; i < r; i++) {
        if (good[i] > B) good[i] = 1; 
        else good[i] = 0;
    }
    dfs_init(0, -1);
    dfs_merge(0, -1);
    map<int, int> init;
    dfs_path(0, -1, init);
    for (int i = 0; i < q; i++) {
        int qu, qv; cin >> qu >> qv;
        qu--, qv--;
        if (!good[qu] && !good[qv]) {
            int ret = 0;
            for (auto p : locs[qv]) {
                orz.upd(st[p] + 1, 1);
                // dbg(st[p], 1);
            }
            for (auto p : locs[qu]) {
                ret += orz.query(st[p] + 1, st[p] + sz[p]);
                // dbg(st[p], st[p] + sz[p] - 1);
            }
            for (auto p : locs[qv]) {
                orz.upd(st[p] + 1, -1);
                // dbg(st[p], -1);
            }
            cout << ret << endl;
        } else {
            assert(pre.find(mp(qu, qv)) != pre.end());
            cout << pre[mp(qu, qv)] << endl;
        }
    }
}

• Subtask 1: 15 / 15
• Subtask 2: 40 / 85