Submission #768226

#	Time	Username	Problem	Language	Result	Execution time	Memory
768226		AdamGS	Bitaro’s Party (JOI18_bitaro)	C++17	100 / 100	850 ms	175948 KiB

bitaro

#include<bits/stdc++.h>
using namespace std;
#define rep(a, b) for(int a = 0; a < (b); ++a)
#define st first
#define nd second
#define pb push_back
#define all(a) a.begin(), a.end()
const int LIM=1e5+7, K=200, INF=1e9+7;
vector<int>V[LIM];
vector<pair<int,int>>P[LIM];
int odw[LIM], kiedy[LIM], czy[LIM], najd[LIM], akt, akt2;
void lacz(int a, int b) {
	++akt;
	vector<pair<int,int>>tmp;
	int la=0, lb=0;
	while(tmp.size()<200 && (la<P[a].size() || lb<P[b].size())) {
		if(lb==P[b].size() || la<P[a].size() && P[a][la].nd>=P[b][lb].nd+1) {
			if(kiedy[P[a][la].st]<akt) {
				kiedy[P[a][la].st]=akt;
				tmp.pb(P[a][la]);
			}
			++la;
		} else {
			if(kiedy[P[b][lb].st]<akt) {
				kiedy[P[b][lb].st]=akt;
				tmp.pb({P[b][lb].st, P[b][lb].nd+1});
			}
			++lb;
		}
	}
	P[a]=tmp;
}
void DFS(int x) {
	odw[x]=1;
	P[x].pb({x, 0});
	for(auto i : V[x]) {
		if(!odw[i]) DFS(i);
		lacz(x, i);
	}
}
void DFS2(int x) {
	odw[x]=1;
	najd[x]=0;
	if(czy[x]==akt2) najd[x]=-INF;
	for(auto i : V[x]) {
		if(!odw[i]) DFS2(i);
		najd[x]=max(najd[x], najd[i]+1);
	}
}
int main() {
	ios_base::sync_with_stdio(0); cin.tie(0);
	int n, m, q;
	cin >> n >> m >> q;
	while(m--) {
		int a, b;
		cin >> a >> b; --a; --b;
		V[b].pb(a);
	}
	rep(i, n) if(!odw[i]) DFS(i);
	while(q--) {
		int x, y;
		cin >> x >> y; --x;
		++akt2;
		rep(i, y) {
			int a;
			cin >> a; --a;
			czy[a]=akt2;
		}
		if(y<K) {
			int ans=-1;
			for(auto i : P[x]) if(czy[i.st]<akt2) ans=max(ans, i.nd);
			cout << ans << '\n';
			continue;
		}
		rep(i, n) odw[i]=0;
		DFS2(x);
		cout << max(najd[x], -1) << '\n';
	}
}

Compilation message (stderr)

bitaro.cpp: In function 'void lacz(int, int)':
bitaro.cpp:16:29: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   16 |  while(tmp.size()<200 && (la<P[a].size() || lb<P[b].size())) {
      |                           ~~^~~~~~~~~~~~
bitaro.cpp:16:47: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   16 |  while(tmp.size()<200 && (la<P[a].size() || lb<P[b].size())) {
      |                                             ~~^~~~~~~~~~~~
bitaro.cpp:17:8: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   17 |   if(lb==P[b].size() || la<P[a].size() && P[a][la].nd>=P[b][lb].nd+1) {
      |      ~~^~~~~~~~~~~~~
bitaro.cpp:17:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   17 |   if(lb==P[b].size() || la<P[a].size() && P[a][la].nd>=P[b][lb].nd+1) {
      |                         ~~^~~~~~~~~~~~
bitaro.cpp:17:40: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   17 |   if(lb==P[b].size() || la<P[a].size() && P[a][la].nd>=P[b][lb].nd+1) {
      |                         ~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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