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Submission #369372

# Submission time Handle Problem Language Result Execution time Memory
369372 2021-02-21T13:04:40 Z AmineWeslati Regions (IOI09_regions) C++14
100 / 100
 4491 ms 55660 KB 
//Never stop trying
#include "bits/stdc++.h"
using namespace std;
#define boost ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0)

typedef long long ll;
typedef string str;
typedef long double ld;
typedef pair<int, int> pi;
#define fi first
#define se second
typedef vector<int> vi;
typedef vector<pi> vpi;
#define pb push_back
#define eb emplace_back
#define sz(x) (int)x.size()
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
#define endl "\n"
#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)

const int MOD = 1e9 + 7; //998244353
const ll INF = 1e18;
const int MX = 2e5 + 10;
const int nx[4] = {0, 0, 1, -1}, ny[4] = {1, -1, 0, 0}; //right left down up

template<class T> using V = vector<T>;
template<class T> bool ckmin(T& a, const T& b) { return a > b ? a = b, 1 : 0; }
template<class T> bool ckmax(T& a, const T& b) { return a < b ? a = b, 1 : 0; }
ll cdiv(ll a, ll b) { return a / b + ((a ^ b) > 0 && a % b); } // divide a by b rounded up
//constexpr int log2(int x) { return 31 - __builtin_clz(x); } // floor(log2(x))

mt19937 rng(chrono::system_clock::now().time_since_epoch().count());
//mt19937_64 rng(chrono::system_clock::now().time_since_epoch().count());
ll random(ll a, ll b){
    return a + rng() % (b - a + 1);
}
#ifndef LOCAL  
#define cerr if(false) cerr
#endif
#define dbg(x) cerr << #x << " : " << x << endl; 
#define dbgs(x,y) cerr << #x << " : " << x << " / " << #y << " : " << y << endl;
#define dbgv(v) cerr << #v << " : " << "[ "; for(auto it : v) cerr << it << ' '; cerr << ']' << endl;
#define here() cerr << "here" << endl;

void IO() {
#ifdef LOCAL
    freopen("input.txt", "r", stdin); 
    freopen("output.txt", "w", stdout);
#endif
}
/////////////////////////ONLY CLEAN CODES ALLOWED/////////////////////////

const int C=400;
int N,R,Q; 
vi a(MX),adj[MX],cnt(MX,0),vec[MX],vec2[MX],in(MX),out(MX);
V<ll>mp[MX];

//mp[x][y]
void dfs(int u, int c, ll nb){
	for(auto v: adj[u]){
		mp[c][a[v]]+=nb;
		dfs(v,c,nb+(a[v]==c));
	}
}
void precompute1(){ 
	FOR(i,1,R+1) if(cnt[i]>C){
		mp[i].assign(R+1,0);
		dfs(1,i,(a[1]==i));
	}
}

//in[u],out[u]
//vec2[c]
int cntr=0;
void euler(int u=1, int p=1){
	in[u]=++cntr;
	for(auto v: adj[u]) euler(v,u);
	out[u]=cntr;
}
void precompute2(){ 
	euler();
	FOR(i,1,N+1) vec2[a[i]].pb(in[i]);
	FOR(i,1,R+1) sort(all(vec2[i]));
}


ll solve(int l, int r, int c){
	if(l>r) return 0;
	return upper_bound(all(vec2[c]),r)-lower_bound(all(vec2[c]),l);
}

int main() {
    boost; IO();

    cin>>N>>R>>Q;
    FOR(i,1,N+1){
    	if(i>1){
    		int j; cin>>j;
    		adj[j].pb(i);
    	}
    	cin>>a[i];
    	vec[a[i]].pb(i);
    	cnt[a[i]]++;
    }

    precompute1(); //(N/C)*N
    precompute2(); 

    //Q*C*lg(N)
    while(Q--){ 
    	int x,y; cin>>x>>y;
    	if(cnt[x]>C){
    		cout << mp[x][y] << endl;
    		cout.flush();
    	}
    	else{
    		ll ans=0;
    		for(auto u: vec[x]){
    			int l=in[u],r=out[u];
    			ans+=solve(l+1,r,y);
    		}
    		cout << ans << endl;
    		cout.flush();
    	}
    }

    return 0;
}
//Change your approach

Subtask #1
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 16 ms 22252 KB Output is correct
2 Correct 16 ms 22252 KB Output is correct
3 Correct 17 ms 22252 KB Output is correct
4 Correct 19 ms 22252 KB Output is correct
5 Correct 22 ms 22252 KB Output is correct
6 Correct 32 ms 22380 KB Output is correct
7 Correct 44 ms 22380 KB Output is correct
8 Correct 44 ms 22380 KB Output is correct
9 Correct 61 ms 22764 KB Output is correct
10 Correct 95 ms 22892 KB Output is correct
11 Correct 144 ms 23020 KB Output is correct
12 Correct 165 ms 23532 KB Output is correct
13 Correct 185 ms 23148 KB Output is correct
14 Correct 333 ms 23660 KB Output is correct
15 Correct 303 ms 26092 KB Output is correct

Subtask #2
85.0 / 85.0

# Verdict Execution time Memory Grader output
1 Correct 1796 ms 26424 KB Output is correct
2 Correct 1916 ms 24812 KB Output is correct
3 Correct 3315 ms 28328 KB Output is correct
4 Correct 325 ms 23672 KB Output is correct
5 Correct 391 ms 25196 KB Output is correct
6 Correct 739 ms 28012 KB Output is correct
7 Correct 1574 ms 27672 KB Output is correct
8 Correct 1150 ms 39020 KB Output is correct
9 Correct 2819 ms 29996 KB Output is correct
10 Correct 4062 ms 55660 KB Output is correct
11 Correct 4491 ms 29300 KB Output is correct
12 Correct 1702 ms 31084 KB Output is correct
13 Correct 2412 ms 31524 KB Output is correct
14 Correct 3010 ms 34428 KB Output is correct
15 Correct 4224 ms 36588 KB Output is correct
16 Correct 4005 ms 43756 KB Output is correct
17 Correct 3652 ms 45676 KB Output is correct