Submission #888056

#	Time	Username	Problem	Language	Result	Execution time	Memory
888056		PM1	Bitaro’s Party (JOI18_bitaro)	C++17	100 / 100	657 ms	214608 KiB

bitaro

#include <bits/stdc++.h>
using namespace std;
#define fr first
#define sc second
const int mxn=1e5+5,sq=130;
int n,m,q,mark[mxn];
vector<int>v[mxn];
vector<pair<int,int> >pre[mxn];
int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	cin>>n>>m>>q;
	for(int i=1;i<=m;i++){
		int x,y;
		cin>>x>>y;
		v[y].push_back(x);
	}
	for(int i=1;i<=n;i++){
		int p[v[i].size()];
		memset(p,0,sizeof p);
		pair<int,int>num;
		while(pre[i].size()<sq){
			for(int j=0;j<v[i].size();j++){
				int x=v[i][j];
				if(p[j]>=pre[x].size() )continue;
				while( p[j]<pre[x].size()&&mark[pre[x][p[j]].fr] )p[j]++;//cout<<j<<" "<<p[j]<<endl;
				if(p[j]>=pre[x].size())continue;
				if(pre[x][p[j]].sc+1>=num.sc){
					num.sc=pre[x][p[j]].sc+1;
					num.fr=pre[x][p[j]].fr;
				}
			}
			if(num.fr==0)break;
			mark[num.fr]=1;
			pre[i].push_back(num);
			num={0,0};
		}
		if(pre[i].size()<sq){
			pre[i].push_back({i,0});
			mark[i]=1;
		}
		for(auto j:pre[i]){
			mark[j.fr]=0;
		}
		for(int j=2;j<pre[i].size();j++){
			assert(pre[i][j].sc<=pre[i][j-1].sc);
		}
	}
	while(q--){
		int t,y;
		cin>>t>>y;
		int a[y];
		for(int i=0;i<y;i++){
			cin>>a[i];
			mark[a[i]]=1;
		}
		if(y>=sq){
			int dp[t+1];
			for(int i=1;i<=t;i++){
				dp[i]=(mark[i])?-1e6:0;
				for(auto j:v[i]){
					dp[i]=max(dp[i],dp[j]+1);
				}
			}
			if(dp[t]<0)dp[t]=-1;
			cout<<dp[t]<<'\n';
		}
		else{
			int d=0;
			for(auto i:pre[t]){
				if(!mark[i.fr]){
					d=1;
					cout<<i.sc<<'\n';
					break;
				}
			}
			if(!d)
				cout<<-1<<'\n';
		}
		for(int i=0;i<y;i++)
			mark[a[i]]=0;
	}
}

Compilation message (stderr)

bitaro.cpp: In function 'int main()':
bitaro.cpp:24:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   24 |    for(int j=0;j<v[i].size();j++){
      |                ~^~~~~~~~~~~~
bitaro.cpp:26:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   26 |     if(p[j]>=pre[x].size() )continue;
      |        ~~~~^~~~~~~~~~~~~~~
bitaro.cpp:27:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   27 |     while( p[j]<pre[x].size()&&mark[pre[x][p[j]].fr] )p[j]++;//cout<<j<<" "<<p[j]<<endl;
      |            ~~~~^~~~~~~~~~~~~~
bitaro.cpp:28:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   28 |     if(p[j]>=pre[x].size())continue;
      |        ~~~~^~~~~~~~~~~~~~~
bitaro.cpp:46:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   46 |   for(int j=2;j<pre[i].size();j++){
      |               ~^~~~~~~~~~~~~~

• Subtask 1: 7 / 7
• Subtask 2: 7 / 7
• Subtask 3: 86 / 86