제출 #967901

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
967901		8pete8	Regions (IOI09_regions)	C++17	3 / 100	2653 ms	108828 KiB

regions

#include<iostream>
#include<stack>
#include<map>
#include<vector>
#include<string>
#include<unordered_map>
#include <queue>
#include<cstring>
#include<limits.h>
#include <cassert>
#include<cmath>
#include<set>
#include<algorithm>
#include <iomanip>
#include<numeric> //gcd(a,b)
#include<bitset>
#include <cstdlib> 
#include <cstdint>
using namespace std;
#define ll long long
#define f first
//#define endl "\n"
#define s second
#define pii pair<int,int>
#define ppii pair<int,pii>
#define vi vector<int>
#define pb push_back
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define F(n) for(int i=0;i<n;i++)
#define lb lower_bound
#define ub upper_bound
#define fastio ios::sync_with_stdio(false);cin.tie(NULL);
#pragma GCC optimize ("03,unroll-loops")
using namespace std;
//#define int long long
//#define double long double
const int mod=1e9+7,mxn=2e5+5,lg=60,inf=1e9,minf=-1e9,mx=3e4;
int root=700,st;
vector<int>adj[mxn+10];
int re[mxn+10],recnt[mxn+10],sz[mxn+10],hvyp[mxn+10],up[mxn+10];
int tin[mxn+10],tout[mxn+10],T=0;
void getsz(int cur){sz[cur]=1;for(auto i:adj[cur])getsz(i),sz[cur]+=sz[i];}
void dfs(int cur,int hvypa){
	tin[cur]=++T;
	int hvy=0;
	hvyp[cur]=hvypa;
	for(auto i:adj[cur]){
		if(sz[i]>sz[hvy])hvy=i;
		up[i]=cur;
	}
	for(auto i:adj[cur])if(i!=hvy)dfs(i,i);
	if(hvy)dfs(hvy,hvypa);
	tout[cur]=T;
}
bool cmp(int a,int b){return tin[a]<tin[b];}
struct chain{
	vector<int>have,com;
	vector<vector<int>>pos;
	void init(){
		if(have.empty())return;
		for(auto i:have)com.pb(re[i]);
		sort(all(com));
		sort(all(have),cmp);
		com.erase(unique(all(com)),com.end());
		pos.resize(com.size());
		for(auto i:have)pos[lb(all(com),re[i])-com.begin()].pb(tin[i]);
		return;
	}
	int get(int x,int id){
		auto it=lb(all(com),id)-com.begin();
		if(it>=pos.size()||com[it]!=id)return 0;
		if(pos[it].empty())return 0;
		if(pos[it].back()<=x)return pos[it].size();
		else return upper_bound(all(pos[it]),x)-pos[it].begin();
	}
}t[mxn+10];//parent of hvy chain
vector<int>pos[mxn+10];
vector<int>have[mxn+10];
int pre[mx][500];
int32_t main(){
	fastio
	int n,r,q;cin>>n>>r>>q;	
	root=sqrt(n);
	for(int i=1;i<=n;i++){
		if(i!=1){
			int b;cin>>b;
			adj[b].pb(i);
		}
		cin>>re[i];
		recnt[re[i]]++;
		have[re[i]].pb(i);
	}
	getsz(1);
	dfs(1,1);
	for(int i=1;i<=n;i++)t[hvyp[i]].have.pb(i);
	for(int i=1;i<=n;i++)t[i].init(),pos[re[i]].pb(tin[i]);
	vector<int>k;
	for(int i=1;i<=r;i++){
		if(recnt[i]<root)continue;
		k.pb(i);
	}
	for(int i=1;i<=n;i++){
		int cur=i;
		while(hvyp[cur]!=1){
			for(int j=0;j<k.size();j++){
				pre[re[i]][j]+=t[hvyp[cur]].get(tin[cur],k[j]);
			}
			cur=up[hvyp[cur]];
		}
		for(int j=0;j<k.size();j++)pre[re[i]][j]+=t[hvyp[cur]].get(tin[cur],k[j]);
	}
	//qry r1,r2 cout<<pre[r2][pos r1];
	while(q--){
		int a,b;cin>>a>>b;
		if(recnt[a]<root){
			int ans=0;
			for(auto j:have[a]){
				int l=lb(all(pos[b]),tin[j])-pos[b].begin();
				if(l==pos[b].size())continue;
				int r=lb(all(pos[b]),tout[j])-pos[b].begin();
				if(r==pos[b].size())r--;
				ans+=(r-l+1);
			}
			cout<<ans<<endl;
		}
		else{
			auto it=lb(all(k),a)-k.begin();
			cout<<pre[b][it]<<endl;
		}
	}
}
/*
sqrt decomp
if region cnt<=sqrtn -> burte force sqrtn{
	do euler tour keep vector of pos in euler tour for each region
	when qry r1,r2 loop through all sqrtn node then qry in subtree of that node
	qry-> bs l,r in vector of r2; ans+=(r-l+1)
}
else we precompute the region to other region (keep sqrtn(r)){
	use merge sort tree +hld? (too costly?){
		dont need merge sort?
		keep chain then each chain keep vector of pos for each region
	}

}
*/

컴파일 시 표준 에러 (stderr) 메시지

regions.cpp: In member function 'int chain::get(int, int)':
regions.cpp:72:8: warning: comparison of integer expressions of different signedness: 'long int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   72 |   if(it>=pos.size()||com[it]!=id)return 0;
      |      ~~^~~~~~~~~~~~
regions.cpp: In function 'int32_t main()':
regions.cpp:106:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  106 |    for(int j=0;j<k.size();j++){
      |                ~^~~~~~~~~
regions.cpp:111:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  111 |   for(int j=0;j<k.size();j++)pre[re[i]][j]+=t[hvyp[cur]].get(tin[cur],k[j]);
      |               ~^~~~~~~~~
regions.cpp:120:9: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  120 |     if(l==pos[b].size())continue;
      |        ~^~~~~~~~~~~~~~~
regions.cpp:122:9: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  122 |     if(r==pos[b].size())r--;
      |        ~^~~~~~~~~~~~~~~

• Subtask 1: 3 / 15
• Subtask 2: 0 / 85