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답안 #817677

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
817677 2023-08-09T14:59:49 Z MohamedAhmed04 From Hacks to Snitches (BOI21_watchmen) C++14
35 / 100
 6000 ms 197792 KB 
#include <bits/stdc++.h>

using namespace std ;

const int inf = 1e9 ;
const int MAX = 3e5 + 10 ;
const int K = 70 ;

int arr[MAX] ;
int n , m , k ;

vector< vector<int> >adj(MAX) ;

vector<int>v[MAX] ;
int watch[MAX] , cycle_sz[MAX] , id[MAX] ;

int dist[MAX][K] ;

int calc[MAX][K] ;

bool check(int node , int child , int tim)
{
	assert(watch[child] != 0) ;
	int x = watch[node] ;
	int tim_node = 2e9 ;
	if(watch[node])
	{
		int cur = tim % cycle_sz[x] ;
		tim_node = tim + (id[node] - cur + cycle_sz[x]) % cycle_sz[x] ;
	}
	int tim_child = -2e9 ;
	x = watch[child] ;
	int cur = tim % cycle_sz[x] ;
	tim_child = tim + (id[child] - cur + cycle_sz[x]) % cycle_sz[x] ;
	return (tim_child < tim_node-1 || (tim_child == tim_node - 1 && watch[child] != watch[node])) ;
}

void solve(int src)
{
	for(int i = 1 ; i <= n ; ++i)
		dist[i][0] = dist[i][1] = inf ;
	priority_queue< array<int , 3> , vector< array<int , 3> > , greater< array<int , 3> > >q ;
	dist[src][0] = 0 ;
	q.push({0 , src , 0}) ;
	while(!q.empty())
	{
		array<int , 3>a = q.top() ;
		q.pop() ;
		int node = a[1] , cost = a[0] , t = a[2] ;
		if(dist[node][t] < cost)
			continue ;
		for(auto &child : adj[node])
		{
			int child2 = child ;
			int cost2 = cost + 1 ;
			if((!watch[child2]))
			{
				if(cost2 < dist[child2][0])
				{
					dist[child2][0] = cost2 ;
					q.push({cost2 , child2 , 0}) ;
				}
				continue ;
			}
			int x = watch[child2] ;
			if(check(node , child2 , cost)) //handle waiting for some time
			{
				int cur = cost % cycle_sz[x] ;
				cost2 = cost + (id[child2] - cur + cycle_sz[x]) % cycle_sz[x] + 1 ; 
				if(cost2 < dist[child2][1])
				{
					dist[child2][1] = cost2 ;
					q.push({cost2 , child2 , 1}) ;
				}
			}
			cost2 = cost + 1 ;
			//handle corridor 
			if(v[x][(cost2 - 1) % cycle_sz[x]] == child2 && v[x][cost2 % cycle_sz[x]] == node)
				continue ;
			if(v[x][cost2 % cycle_sz[x]] != child2) //go without waiting
			{
				if(cost2 < dist[child2][t])
				{
					dist[child2][t] = cost2 ;
					q.push({cost2 , child2 , t}) ;
				}
			}
		}
	}
}

void solve2(int src)
{
	for(int i = 1 ; i <= n ; ++i)
	{
		for(int j = 0 ; j < K ; ++j)
			dist[i][j] = inf ;
	}
	queue< pair<int , int> >q ;
	dist[src][0] = 0 ;
	q.push({src , 0}) ;
	while(!q.empty())
	{
		pair<int , int>p = q.front() ;
		q.pop() ;
		int node = p.first , wait = p.second ;
		int cost = dist[node][wait] , x = watch[node] ;
		if(node == n)
			return ;
		if((!x) || (v[x][calc[cost + 1][cycle_sz[x]]] != node))
		{
			if(wait+1 < K && dist[node][wait+1] == inf)
			{
				dist[node][wait+1] = cost + 1 ;
				q.push({node , wait+1}) ;
			}
		}
		for(auto &child : adj[node])
		{
			int child2 = child ;
			int cost2 = cost + 1 ;
			x = watch[child] ;
			if(x > 0 && v[x][calc[cost2 - 1][cycle_sz[x]]] == child2 && v[x][calc[cost2][cycle_sz[x]]] == node)
				continue ;
			if(x > 0 && v[x][calc[cost2][cycle_sz[x]]] == child2)
				continue ;
			if(dist[child2][wait] == inf)
			{
				dist[child2][wait] = cost2 ;
				q.push({child2 , wait}) ;
			}
		}
	}
}

int main()
{
	ios_base::sync_with_stdio(0) ;
	cin.tie(0) ;
	cin>>n>>m ;
	for(int i = 0 ; i < m ; ++i)
	{
		int x , y ;
		cin>>x>>y ;
		adj[x].push_back(y) ;
		adj[y].push_back(x) ;
	}
	cin>>k ;
	for(int i = 1 ; i <= k ; ++i)
	{
		cin>>cycle_sz[i] ;
		v[i].resize(cycle_sz[i]) ;
		for(int j = 0 ; j < cycle_sz[i] ; ++j)
		{
			cin>>v[i][j] ;
			watch[v[i][j]] = i ;
			id[v[i][j]] = j ;
		}
	}
	bool flag = true ;
	for(int i = 1 ; i <= n ; ++i)
	{
		for(auto &child : adj[i])
			flag &= (watch[i] == 0 || watch[child] == 0 || watch[i] == watch[child]) ;
	}
	if(flag) //no corridor connects two two different routes
	{
		solve(1) ;
		if(dist[n][0] == inf)
			cout<<"impossible\n" ;
		else
			cout<<dist[n][0]<<"\n" ;
	}
	else
	{
		for(int j = 1 ; j < K ; ++j)
		{
			calc[0][j] = 0 ;
			for(int i = 1 ; i < n + 1000 ; ++i)
			{
				calc[i][j] = calc[i-1][j] + 1 ;
				if(calc[i][j] == j)
					calc[i][j] = 0 ;
			}
		}
		solve2(1) ;
		int ans = inf ;
		for(int i = 0 ; i < K ; ++i)
			ans = min(ans , dist[n][i]) ;
		if(ans == inf)
			cout<<"impossible\n" ;
		else
			cout<<ans<<"\n" ;
	}
	return 0 ;
}

Subtask #1
5.0 / 5.0

# 결과 실행 시간 메모리 Grader output
1 Correct 17 ms 15444 KB Output is correct
2 Correct 74 ms 45500 KB Output is correct
3 Correct 77 ms 42596 KB Output is correct
4 Correct 70 ms 42660 KB Output is correct
5 Correct 8 ms 14420 KB Output is correct
6 Correct 69 ms 42544 KB Output is correct

Subtask #2
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 18 ms 15504 KB Output is correct
2 Correct 59 ms 45468 KB Output is correct
3 Correct 59 ms 42516 KB Output is correct
4 Correct 62 ms 42732 KB Output is correct
5 Correct 7 ms 14420 KB Output is correct
6 Correct 61 ms 42572 KB Output is correct
7 Correct 81 ms 42628 KB Output is correct
8 Correct 57 ms 42636 KB Output is correct
9 Correct 60 ms 42548 KB Output is correct
10 Correct 59 ms 42784 KB Output is correct
11 Correct 59 ms 42624 KB Output is correct
12 Correct 85 ms 42792 KB Output is correct

Subtask #3
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 18 ms 15504 KB Output is correct
2 Correct 59 ms 45468 KB Output is correct
3 Correct 59 ms 42516 KB Output is correct
4 Correct 62 ms 42732 KB Output is correct
5 Correct 7 ms 14420 KB Output is correct
6 Correct 61 ms 42572 KB Output is correct
7 Correct 81 ms 42628 KB Output is correct
8 Correct 57 ms 42636 KB Output is correct
9 Correct 60 ms 42548 KB Output is correct
10 Correct 59 ms 42784 KB Output is correct
11 Correct 59 ms 42624 KB Output is correct
12 Correct 85 ms 42792 KB Output is correct
13 Correct 19 ms 15488 KB Output is correct
14 Correct 62 ms 45404 KB Output is correct
15 Correct 60 ms 42572 KB Output is correct
16 Correct 66 ms 42724 KB Output is correct
17 Correct 7 ms 14452 KB Output is correct
18 Correct 65 ms 42552 KB Output is correct
19 Correct 64 ms 42616 KB Output is correct
20 Correct 76 ms 42584 KB Output is correct
21 Correct 59 ms 42528 KB Output is correct
22 Correct 63 ms 42800 KB Output is correct
23 Correct 60 ms 42700 KB Output is correct
24 Correct 60 ms 42572 KB Output is correct
25 Correct 968 ms 127732 KB Output is correct
26 Correct 924 ms 134228 KB Output is correct
27 Correct 886 ms 127588 KB Output is correct
28 Correct 773 ms 132556 KB Output is correct
29 Correct 1043 ms 121468 KB Output is correct
30 Correct 955 ms 124872 KB Output is correct
31 Correct 1050 ms 134704 KB Output is correct

Subtask #4
10.0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Correct 18 ms 15504 KB Output is correct
2 Correct 59 ms 45468 KB Output is correct
3 Correct 59 ms 42516 KB Output is correct
4 Correct 62 ms 42732 KB Output is correct
5 Correct 7 ms 14420 KB Output is correct
6 Correct 61 ms 42572 KB Output is correct
7 Correct 81 ms 42628 KB Output is correct
8 Correct 57 ms 42636 KB Output is correct
9 Correct 60 ms 42548 KB Output is correct
10 Correct 59 ms 42784 KB Output is correct
11 Correct 59 ms 42624 KB Output is correct
12 Correct 85 ms 42792 KB Output is correct
13 Correct 19 ms 15488 KB Output is correct
14 Correct 62 ms 45404 KB Output is correct
15 Correct 60 ms 42572 KB Output is correct
16 Correct 66 ms 42724 KB Output is correct
17 Correct 7 ms 14452 KB Output is correct
18 Correct 65 ms 42552 KB Output is correct
19 Correct 64 ms 42616 KB Output is correct
20 Correct 76 ms 42584 KB Output is correct
21 Correct 59 ms 42528 KB Output is correct
22 Correct 63 ms 42800 KB Output is correct
23 Correct 60 ms 42700 KB Output is correct
24 Correct 60 ms 42572 KB Output is correct
25 Correct 968 ms 127732 KB Output is correct
26 Correct 924 ms 134228 KB Output is correct
27 Correct 886 ms 127588 KB Output is correct
28 Correct 773 ms 132556 KB Output is correct
29 Correct 1043 ms 121468 KB Output is correct
30 Correct 955 ms 124872 KB Output is correct
31 Correct 1050 ms 134704 KB Output is correct
32 Correct 18 ms 15444 KB Output is correct
33 Correct 66 ms 45400 KB Output is correct
34 Correct 67 ms 42612 KB Output is correct
35 Correct 63 ms 42772 KB Output is correct
36 Correct 8 ms 14420 KB Output is correct
37 Correct 62 ms 42536 KB Output is correct
38 Correct 61 ms 42620 KB Output is correct
39 Correct 62 ms 42568 KB Output is correct
40 Correct 57 ms 42488 KB Output is correct
41 Correct 61 ms 42784 KB Output is correct
42 Correct 68 ms 42700 KB Output is correct
43 Correct 62 ms 42520 KB Output is correct
44 Correct 1321 ms 127768 KB Output is correct
45 Correct 1352 ms 134248 KB Output is correct
46 Correct 1048 ms 127600 KB Output is correct
47 Correct 864 ms 132484 KB Output is correct
48 Correct 1106 ms 121364 KB Output is correct
49 Correct 1138 ms 124896 KB Output is correct
50 Correct 1066 ms 134736 KB Output is correct
51 Correct 1090 ms 128644 KB Output is correct
52 Correct 1000 ms 135156 KB Output is correct
53 Correct 953 ms 127316 KB Output is correct
54 Correct 800 ms 121132 KB Output is correct
55 Correct 1435 ms 127240 KB Output is correct
56 Correct 1293 ms 120944 KB Output is correct

Subtask #5
0 / 25.0

# 결과 실행 시간 메모리 Grader output
1 Correct 17 ms 15444 KB Output is correct
2 Correct 74 ms 45500 KB Output is correct
3 Correct 77 ms 42596 KB Output is correct
4 Correct 70 ms 42660 KB Output is correct
5 Correct 8 ms 14420 KB Output is correct
6 Correct 69 ms 42544 KB Output is correct
7 Correct 18 ms 15504 KB Output is correct
8 Correct 59 ms 45468 KB Output is correct
9 Correct 59 ms 42516 KB Output is correct
10 Correct 62 ms 42732 KB Output is correct
11 Correct 7 ms 14420 KB Output is correct
12 Correct 61 ms 42572 KB Output is correct
13 Correct 81 ms 42628 KB Output is correct
14 Correct 57 ms 42636 KB Output is correct
15 Correct 60 ms 42548 KB Output is correct
16 Correct 59 ms 42784 KB Output is correct
17 Correct 59 ms 42624 KB Output is correct
18 Correct 85 ms 42792 KB Output is correct
19 Correct 6 ms 14420 KB Output is correct
20 Correct 7 ms 14352 KB Output is correct
21 Correct 8 ms 14676 KB Output is correct
22 Correct 17 ms 15512 KB Output is correct
23 Correct 108 ms 45500 KB Output is correct
24 Correct 110 ms 42636 KB Output is correct
25 Correct 65 ms 42684 KB Output is correct
26 Correct 6 ms 14408 KB Output is correct
27 Correct 85 ms 42516 KB Output is correct
28 Correct 76 ms 42620 KB Output is correct
29 Correct 74 ms 42628 KB Output is correct
30 Correct 72 ms 42572 KB Output is correct
31 Correct 58 ms 42784 KB Output is correct
32 Correct 78 ms 42696 KB Output is correct
33 Correct 62 ms 42636 KB Output is correct
34 Execution timed out 6035 ms 197792 KB Time limit exceeded
35 Halted 0 ms 0 KB -

Subtask #6
0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 17 ms 15444 KB Output is correct
2 Correct 74 ms 45500 KB Output is correct
3 Correct 77 ms 42596 KB Output is correct
4 Correct 70 ms 42660 KB Output is correct
5 Correct 8 ms 14420 KB Output is correct
6 Correct 69 ms 42544 KB Output is correct
7 Correct 18 ms 15504 KB Output is correct
8 Correct 59 ms 45468 KB Output is correct
9 Correct 59 ms 42516 KB Output is correct
10 Correct 62 ms 42732 KB Output is correct
11 Correct 7 ms 14420 KB Output is correct
12 Correct 61 ms 42572 KB Output is correct
13 Correct 81 ms 42628 KB Output is correct
14 Correct 57 ms 42636 KB Output is correct
15 Correct 60 ms 42548 KB Output is correct
16 Correct 59 ms 42784 KB Output is correct
17 Correct 59 ms 42624 KB Output is correct
18 Correct 85 ms 42792 KB Output is correct
19 Correct 19 ms 15488 KB Output is correct
20 Correct 62 ms 45404 KB Output is correct
21 Correct 60 ms 42572 KB Output is correct
22 Correct 66 ms 42724 KB Output is correct
23 Correct 7 ms 14452 KB Output is correct
24 Correct 65 ms 42552 KB Output is correct
25 Correct 64 ms 42616 KB Output is correct
26 Correct 76 ms 42584 KB Output is correct
27 Correct 59 ms 42528 KB Output is correct
28 Correct 63 ms 42800 KB Output is correct
29 Correct 60 ms 42700 KB Output is correct
30 Correct 60 ms 42572 KB Output is correct
31 Correct 968 ms 127732 KB Output is correct
32 Correct 924 ms 134228 KB Output is correct
33 Correct 886 ms 127588 KB Output is correct
34 Correct 773 ms 132556 KB Output is correct
35 Correct 1043 ms 121468 KB Output is correct
36 Correct 955 ms 124872 KB Output is correct
37 Correct 1050 ms 134704 KB Output is correct
38 Correct 6 ms 14420 KB Output is correct
39 Correct 7 ms 14352 KB Output is correct
40 Correct 8 ms 14676 KB Output is correct
41 Correct 17 ms 15512 KB Output is correct
42 Correct 108 ms 45500 KB Output is correct
43 Correct 110 ms 42636 KB Output is correct
44 Correct 65 ms 42684 KB Output is correct
45 Correct 6 ms 14408 KB Output is correct
46 Correct 85 ms 42516 KB Output is correct
47 Correct 76 ms 42620 KB Output is correct
48 Correct 74 ms 42628 KB Output is correct
49 Correct 72 ms 42572 KB Output is correct
50 Correct 58 ms 42784 KB Output is correct
51 Correct 78 ms 42696 KB Output is correct
52 Correct 62 ms 42636 KB Output is correct
53 Execution timed out 6035 ms 197792 KB Time limit exceeded
54 Halted 0 ms 0 KB -

Subtask #7
0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 17 ms 15444 KB Output is correct
2 Correct 74 ms 45500 KB Output is correct
3 Correct 77 ms 42596 KB Output is correct
4 Correct 70 ms 42660 KB Output is correct
5 Correct 8 ms 14420 KB Output is correct
6 Correct 69 ms 42544 KB Output is correct
7 Correct 18 ms 15504 KB Output is correct
8 Correct 59 ms 45468 KB Output is correct
9 Correct 59 ms 42516 KB Output is correct
10 Correct 62 ms 42732 KB Output is correct
11 Correct 7 ms 14420 KB Output is correct
12 Correct 61 ms 42572 KB Output is correct
13 Correct 81 ms 42628 KB Output is correct
14 Correct 57 ms 42636 KB Output is correct
15 Correct 60 ms 42548 KB Output is correct
16 Correct 59 ms 42784 KB Output is correct
17 Correct 59 ms 42624 KB Output is correct
18 Correct 85 ms 42792 KB Output is correct
19 Correct 19 ms 15488 KB Output is correct
20 Correct 62 ms 45404 KB Output is correct
21 Correct 60 ms 42572 KB Output is correct
22 Correct 66 ms 42724 KB Output is correct
23 Correct 7 ms 14452 KB Output is correct
24 Correct 65 ms 42552 KB Output is correct
25 Correct 64 ms 42616 KB Output is correct
26 Correct 76 ms 42584 KB Output is correct
27 Correct 59 ms 42528 KB Output is correct
28 Correct 63 ms 42800 KB Output is correct
29 Correct 60 ms 42700 KB Output is correct
30 Correct 60 ms 42572 KB Output is correct
31 Correct 968 ms 127732 KB Output is correct
32 Correct 924 ms 134228 KB Output is correct
33 Correct 886 ms 127588 KB Output is correct
34 Correct 773 ms 132556 KB Output is correct
35 Correct 1043 ms 121468 KB Output is correct
36 Correct 955 ms 124872 KB Output is correct
37 Correct 1050 ms 134704 KB Output is correct
38 Correct 18 ms 15444 KB Output is correct
39 Correct 66 ms 45400 KB Output is correct
40 Correct 67 ms 42612 KB Output is correct
41 Correct 63 ms 42772 KB Output is correct
42 Correct 8 ms 14420 KB Output is correct
43 Correct 62 ms 42536 KB Output is correct
44 Correct 61 ms 42620 KB Output is correct
45 Correct 62 ms 42568 KB Output is correct
46 Correct 57 ms 42488 KB Output is correct
47 Correct 61 ms 42784 KB Output is correct
48 Correct 68 ms 42700 KB Output is correct
49 Correct 62 ms 42520 KB Output is correct
50 Correct 1321 ms 127768 KB Output is correct
51 Correct 1352 ms 134248 KB Output is correct
52 Correct 1048 ms 127600 KB Output is correct
53 Correct 864 ms 132484 KB Output is correct
54 Correct 1106 ms 121364 KB Output is correct
55 Correct 1138 ms 124896 KB Output is correct
56 Correct 1066 ms 134736 KB Output is correct
57 Correct 1090 ms 128644 KB Output is correct
58 Correct 1000 ms 135156 KB Output is correct
59 Correct 953 ms 127316 KB Output is correct
60 Correct 800 ms 121132 KB Output is correct
61 Correct 1435 ms 127240 KB Output is correct
62 Correct 1293 ms 120944 KB Output is correct
63 Correct 6 ms 14420 KB Output is correct
64 Correct 7 ms 14352 KB Output is correct
65 Correct 8 ms 14676 KB Output is correct
66 Correct 17 ms 15512 KB Output is correct
67 Correct 108 ms 45500 KB Output is correct
68 Correct 110 ms 42636 KB Output is correct
69 Correct 65 ms 42684 KB Output is correct
70 Correct 6 ms 14408 KB Output is correct
71 Correct 85 ms 42516 KB Output is correct
72 Correct 76 ms 42620 KB Output is correct
73 Correct 74 ms 42628 KB Output is correct
74 Correct 72 ms 42572 KB Output is correct
75 Correct 58 ms 42784 KB Output is correct
76 Correct 78 ms 42696 KB Output is correct
77 Correct 62 ms 42636 KB Output is correct
78 Execution timed out 6035 ms 197792 KB Time limit exceeded
79 Halted 0 ms 0 KB -