oj.uz

Submission #954471

# Submission time Handle Problem Language Result Execution time Memory
954471 2024-03-28T02:51:36 Z koukirocks One-Way Streets (CEOI17_oneway) C++17
100 / 100
 72 ms 18548 KB 
#include <bits/stdc++.h>
#define speed ios_base::sync_with_stdio(0); cin.tie(0)
#define all(x) (x).begin(),(x).end()
#define F first
#define S second
//#pragma GCC optimize("O3")
//#pragma GCC target("avx,avx2")
//#pragma GCC target("popcnt")
 
namespace{using namespace std;}
typedef long long ll;
typedef double db;
typedef long double ldb;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

const ll MAX=1e5+10,P=1e9+7;
const ll INF=0x3f3f3f3f,oo=0x3f3f3f3f3f3f3f3f;
const ldb eps=1e-6;

int n,m,pr;
vector<pii> G[MAX];
vector<pii> eg;
int dfn[MAX];
int tme=1;
int low[MAX];
int fa[MAX];
int st[MAX],ed[MAX];
bool vis[MAX];
vector<int> l,r;

void dfsid(int v,int p,int pid) {
	fa[v]=pid;
	dfn[v]=tme++;
	for (auto [i,id]:G[v]) {
		if (i==p) {
			p=-1;
			continue;
		}
		if (dfn[i]!=-1) continue;
		if (vis[i]) continue;
		dfsid(i,v,id);
		st[v]+=st[i];
		ed[v]+=ed[i];
	}
	vis[v]=true;
}

void dfslow(int v,int p) {
//	cout<<v<<" "<<p<<" vp\n";
	low[v]=v;
	for (auto [i,id]:G[v]) {
		if (i==p) {
			p=-1;
			continue;
		}
		if (dfn[i]<dfn[v]) {
//			cout<<v<<" "<<i<<" vi\n";
			if (dfn[i]<dfn[low[v]]) low[v]=i;
			continue;
		}
		if (vis[i]) continue;
		dfslow(i,v);
		if (dfn[low[i]]<dfn[low[v]]) low[v]=low[i];
	}
	vis[v]=true;
}

void dfsans(int v,int p) {
	if (low[v]==v and v!=1) {
//		cout<<v<<" bg\n";
		if (st[v]>ed[v]) {
			auto [a,b]=eg[fa[v]];
			if (v==a) r.push_back(fa[v]);
			else l.push_back(fa[v]);
		}
		if (st[v]<ed[v]) {
			auto [a,b]=eg[fa[v]];
			if (v==b) r.push_back(fa[v]);
			else l.push_back(fa[v]);
		}
	}
	for (auto [i,id]:G[v]) {
		if (i==p) {
			p=-1;
			continue;
		}
		if (dfn[i]<dfn[v]) continue;
		if (vis[i]) continue;
		dfsans(i,v);
	}
	vis[v]=true;
}

int main() {
	speed;
	cin>>n>>m;
	eg.emplace_back(0,0);
	for (int i=1;i<=m;i++) {
		int a,b;
		cin>>a>>b;
		eg.emplace_back(a,b);
		if (a==b) continue;
		G[a].emplace_back(b,i);
		G[b].emplace_back(a,i);
	}
	memset(st,0,sizeof(st));
	memset(ed,0,sizeof(ed));
	cin>>pr;
	for (int i=0;i<pr;i++) {
		int a,b;
		cin>>a>>b;
		st[a]++;
		ed[b]++;
	}
	memset(dfn,-1,sizeof(dfn));
	memset(vis,0,sizeof(vis));
	for (int i=1;i<=n;i++) {
		if (!vis[i]) dfsid(i,0,0);
	}
	memset(vis,0,sizeof(vis));
	for (int i=1;i<=n;i++) {
		if (!vis[i]) dfslow(i,0);
	}
	memset(vis,0,sizeof(vis));
	for (int i=1;i<=n;i++) {
		if (!vis[i]) dfsans(i,0);
	}
//	for (int i=1;i<=n;i++) cout<<dfn[i]<<" ";
//	cout<<" dfn\n";
//	for (int i=1;i<=n;i++) cout<<low[i]<<" ";
//	cout<<" low\n";
//	for (int i:l) cout<<i<<" ";
//	cout<<" l\n";
//	for (int i:r) cout<<i<<" ";
//	cout<<" r\n";
	vector<pair<int,char> > ans;
	for (int i:l) ans.emplace_back(i,'L');
	for (int i:r) ans.emplace_back(i,'R');
	int id=0;
	sort(all(ans));
	for (int i=1;i<=m;i++) {
		if (id<ans.size() and ans[id].F==i) {
			cout<<ans[id].S;
			id++;
		} else cout<<"B";
	}
	return 0;
}
/*
6 4
1 1
1 2
3 4
5 6
4
2 2
2 1
4 3
5 6
*/

Compilation message

oneway.cpp: In function 'int main()':
oneway.cpp:143:9: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, char> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  143 |   if (id<ans.size() and ans[id].F==i) {
      |       ~~^~~~~~~~~~~

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 4700 KB Output is correct
2 Correct 1 ms 4700 KB Output is correct
3 Correct 1 ms 4696 KB Output is correct
4 Correct 2 ms 4700 KB Output is correct
5 Correct 1 ms 4956 KB Output is correct
6 Correct 2 ms 4696 KB Output is correct
7 Correct 1 ms 4956 KB Output is correct
8 Correct 1 ms 4712 KB Output is correct
9 Correct 1 ms 4700 KB Output is correct
10 Correct 1 ms 4700 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 4700 KB Output is correct
2 Correct 1 ms 4700 KB Output is correct
3 Correct 1 ms 4696 KB Output is correct
4 Correct 2 ms 4700 KB Output is correct
5 Correct 1 ms 4956 KB Output is correct
6 Correct 2 ms 4696 KB Output is correct
7 Correct 1 ms 4956 KB Output is correct
8 Correct 1 ms 4712 KB Output is correct
9 Correct 1 ms 4700 KB Output is correct
10 Correct 1 ms 4700 KB Output is correct
11 Correct 30 ms 10696 KB Output is correct
12 Correct 38 ms 11568 KB Output is correct
13 Correct 38 ms 12232 KB Output is correct
14 Correct 43 ms 12496 KB Output is correct
15 Correct 41 ms 12492 KB Output is correct
16 Correct 37 ms 10612 KB Output is correct
17 Correct 39 ms 13148 KB Output is correct
18 Correct 35 ms 10436 KB Output is correct
19 Correct 38 ms 14176 KB Output is correct
20 Correct 33 ms 10900 KB Output is correct
21 Correct 30 ms 10452 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 4700 KB Output is correct
2 Correct 1 ms 4700 KB Output is correct
3 Correct 1 ms 4696 KB Output is correct
4 Correct 2 ms 4700 KB Output is correct
5 Correct 1 ms 4956 KB Output is correct
6 Correct 2 ms 4696 KB Output is correct
7 Correct 1 ms 4956 KB Output is correct
8 Correct 1 ms 4712 KB Output is correct
9 Correct 1 ms 4700 KB Output is correct
10 Correct 1 ms 4700 KB Output is correct
11 Correct 30 ms 10696 KB Output is correct
12 Correct 38 ms 11568 KB Output is correct
13 Correct 38 ms 12232 KB Output is correct
14 Correct 43 ms 12496 KB Output is correct
15 Correct 41 ms 12492 KB Output is correct
16 Correct 37 ms 10612 KB Output is correct
17 Correct 39 ms 13148 KB Output is correct
18 Correct 35 ms 10436 KB Output is correct
19 Correct 38 ms 14176 KB Output is correct
20 Correct 33 ms 10900 KB Output is correct
21 Correct 30 ms 10452 KB Output is correct
22 Correct 56 ms 15556 KB Output is correct
23 Correct 54 ms 13772 KB Output is correct
24 Correct 54 ms 14312 KB Output is correct
25 Correct 72 ms 18548 KB Output is correct
26 Correct 51 ms 15116 KB Output is correct
27 Correct 52 ms 14000 KB Output is correct
28 Correct 30 ms 8912 KB Output is correct
29 Correct 45 ms 11464 KB Output is correct
30 Correct 43 ms 11712 KB Output is correct
31 Correct 45 ms 11972 KB Output is correct
32 Correct 46 ms 14272 KB Output is correct