oj.uz

Submission #817674

# Submission time Handle Problem Language Result Execution time Memory
817674 2023-08-09T14:57:50 Z MohamedAhmed04 From Hacks to Snitches (BOI21_watchmen) C++14
35 / 100
 6000 ms 197940 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((!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

# Verdict Execution time Memory Grader output
1 Correct 18 ms 15700 KB Output is correct
2 Correct 66 ms 45768 KB Output is correct
3 Correct 63 ms 42784 KB Output is correct
4 Correct 62 ms 42984 KB Output is correct
5 Correct 7 ms 14432 KB Output is correct
6 Correct 61 ms 42888 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 15712 KB Output is correct
2 Correct 67 ms 45744 KB Output is correct
3 Correct 68 ms 42848 KB Output is correct
4 Correct 60 ms 43020 KB Output is correct
5 Correct 8 ms 14432 KB Output is correct
6 Correct 61 ms 42844 KB Output is correct
7 Correct 59 ms 42872 KB Output is correct
8 Correct 61 ms 42808 KB Output is correct
9 Correct 76 ms 42828 KB Output is correct
10 Correct 62 ms 43040 KB Output is correct
11 Correct 62 ms 42856 KB Output is correct
12 Correct 64 ms 42772 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 15712 KB Output is correct
2 Correct 67 ms 45744 KB Output is correct
3 Correct 68 ms 42848 KB Output is correct
4 Correct 60 ms 43020 KB Output is correct
5 Correct 8 ms 14432 KB Output is correct
6 Correct 61 ms 42844 KB Output is correct
7 Correct 59 ms 42872 KB Output is correct
8 Correct 61 ms 42808 KB Output is correct
9 Correct 76 ms 42828 KB Output is correct
10 Correct 62 ms 43040 KB Output is correct
11 Correct 62 ms 42856 KB Output is correct
12 Correct 64 ms 42772 KB Output is correct
13 Correct 17 ms 15732 KB Output is correct
14 Correct 74 ms 45700 KB Output is correct
15 Correct 65 ms 42880 KB Output is correct
16 Correct 79 ms 42916 KB Output is correct
17 Correct 8 ms 14388 KB Output is correct
18 Correct 64 ms 42792 KB Output is correct
19 Correct 72 ms 42992 KB Output is correct
20 Correct 63 ms 42888 KB Output is correct
21 Correct 58 ms 42772 KB Output is correct
22 Correct 61 ms 42984 KB Output is correct
23 Correct 62 ms 42828 KB Output is correct
24 Correct 66 ms 42868 KB Output is correct
25 Correct 1162 ms 128220 KB Output is correct
26 Correct 1042 ms 134648 KB Output is correct
27 Correct 1077 ms 127612 KB Output is correct
28 Correct 903 ms 132400 KB Output is correct
29 Correct 1086 ms 121384 KB Output is correct
30 Correct 1107 ms 124964 KB Output is correct
31 Correct 1214 ms 134772 KB Output is correct

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 15712 KB Output is correct
2 Correct 67 ms 45744 KB Output is correct
3 Correct 68 ms 42848 KB Output is correct
4 Correct 60 ms 43020 KB Output is correct
5 Correct 8 ms 14432 KB Output is correct
6 Correct 61 ms 42844 KB Output is correct
7 Correct 59 ms 42872 KB Output is correct
8 Correct 61 ms 42808 KB Output is correct
9 Correct 76 ms 42828 KB Output is correct
10 Correct 62 ms 43040 KB Output is correct
11 Correct 62 ms 42856 KB Output is correct
12 Correct 64 ms 42772 KB Output is correct
13 Correct 17 ms 15732 KB Output is correct
14 Correct 74 ms 45700 KB Output is correct
15 Correct 65 ms 42880 KB Output is correct
16 Correct 79 ms 42916 KB Output is correct
17 Correct 8 ms 14388 KB Output is correct
18 Correct 64 ms 42792 KB Output is correct
19 Correct 72 ms 42992 KB Output is correct
20 Correct 63 ms 42888 KB Output is correct
21 Correct 58 ms 42772 KB Output is correct
22 Correct 61 ms 42984 KB Output is correct
23 Correct 62 ms 42828 KB Output is correct
24 Correct 66 ms 42868 KB Output is correct
25 Correct 1162 ms 128220 KB Output is correct
26 Correct 1042 ms 134648 KB Output is correct
27 Correct 1077 ms 127612 KB Output is correct
28 Correct 903 ms 132400 KB Output is correct
29 Correct 1086 ms 121384 KB Output is correct
30 Correct 1107 ms 124964 KB Output is correct
31 Correct 1214 ms 134772 KB Output is correct
32 Correct 18 ms 15444 KB Output is correct
33 Correct 61 ms 45476 KB Output is correct
34 Correct 64 ms 42572 KB Output is correct
35 Correct 64 ms 42676 KB Output is correct
36 Correct 7 ms 14420 KB Output is correct
37 Correct 71 ms 42644 KB Output is correct
38 Correct 64 ms 42612 KB Output is correct
39 Correct 63 ms 42620 KB Output is correct
40 Correct 62 ms 42520 KB Output is correct
41 Correct 59 ms 42828 KB Output is correct
42 Correct 61 ms 42700 KB Output is correct
43 Correct 75 ms 42608 KB Output is correct
44 Correct 1110 ms 127844 KB Output is correct
45 Correct 966 ms 134260 KB Output is correct
46 Correct 929 ms 127596 KB Output is correct
47 Correct 775 ms 132460 KB Output is correct
48 Correct 1156 ms 121404 KB Output is correct
49 Correct 1084 ms 124988 KB Output is correct
50 Correct 1221 ms 134660 KB Output is correct
51 Correct 971 ms 128572 KB Output is correct
52 Correct 918 ms 135152 KB Output is correct
53 Correct 927 ms 127408 KB Output is correct
54 Correct 774 ms 121108 KB Output is correct
55 Correct 1137 ms 127292 KB Output is correct
56 Correct 1198 ms 121052 KB Output is correct

Subtask #5
0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 15700 KB Output is correct
2 Correct 66 ms 45768 KB Output is correct
3 Correct 63 ms 42784 KB Output is correct
4 Correct 62 ms 42984 KB Output is correct
5 Correct 7 ms 14432 KB Output is correct
6 Correct 61 ms 42888 KB Output is correct
7 Correct 18 ms 15712 KB Output is correct
8 Correct 67 ms 45744 KB Output is correct
9 Correct 68 ms 42848 KB Output is correct
10 Correct 60 ms 43020 KB Output is correct
11 Correct 8 ms 14432 KB Output is correct
12 Correct 61 ms 42844 KB Output is correct
13 Correct 59 ms 42872 KB Output is correct
14 Correct 61 ms 42808 KB Output is correct
15 Correct 76 ms 42828 KB Output is correct
16 Correct 62 ms 43040 KB Output is correct
17 Correct 62 ms 42856 KB Output is correct
18 Correct 64 ms 42772 KB Output is correct
19 Correct 7 ms 14420 KB Output is correct
20 Correct 7 ms 14420 KB Output is correct
21 Correct 9 ms 14676 KB Output is correct
22 Correct 18 ms 15460 KB Output is correct
23 Correct 71 ms 45392 KB Output is correct
24 Correct 61 ms 42512 KB Output is correct
25 Correct 64 ms 42740 KB Output is correct
26 Correct 7 ms 14420 KB Output is correct
27 Correct 60 ms 42516 KB Output is correct
28 Correct 58 ms 42616 KB Output is correct
29 Correct 65 ms 42532 KB Output is correct
30 Correct 60 ms 42508 KB Output is correct
31 Correct 59 ms 42812 KB Output is correct
32 Correct 68 ms 42696 KB Output is correct
33 Correct 62 ms 42564 KB Output is correct
34 Execution timed out 6061 ms 197940 KB Time limit exceeded
35 Halted 0 ms 0 KB -

Subtask #6
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 15700 KB Output is correct
2 Correct 66 ms 45768 KB Output is correct
3 Correct 63 ms 42784 KB Output is correct
4 Correct 62 ms 42984 KB Output is correct
5 Correct 7 ms 14432 KB Output is correct
6 Correct 61 ms 42888 KB Output is correct
7 Correct 18 ms 15712 KB Output is correct
8 Correct 67 ms 45744 KB Output is correct
9 Correct 68 ms 42848 KB Output is correct
10 Correct 60 ms 43020 KB Output is correct
11 Correct 8 ms 14432 KB Output is correct
12 Correct 61 ms 42844 KB Output is correct
13 Correct 59 ms 42872 KB Output is correct
14 Correct 61 ms 42808 KB Output is correct
15 Correct 76 ms 42828 KB Output is correct
16 Correct 62 ms 43040 KB Output is correct
17 Correct 62 ms 42856 KB Output is correct
18 Correct 64 ms 42772 KB Output is correct
19 Correct 17 ms 15732 KB Output is correct
20 Correct 74 ms 45700 KB Output is correct
21 Correct 65 ms 42880 KB Output is correct
22 Correct 79 ms 42916 KB Output is correct
23 Correct 8 ms 14388 KB Output is correct
24 Correct 64 ms 42792 KB Output is correct
25 Correct 72 ms 42992 KB Output is correct
26 Correct 63 ms 42888 KB Output is correct
27 Correct 58 ms 42772 KB Output is correct
28 Correct 61 ms 42984 KB Output is correct
29 Correct 62 ms 42828 KB Output is correct
30 Correct 66 ms 42868 KB Output is correct
31 Correct 1162 ms 128220 KB Output is correct
32 Correct 1042 ms 134648 KB Output is correct
33 Correct 1077 ms 127612 KB Output is correct
34 Correct 903 ms 132400 KB Output is correct
35 Correct 1086 ms 121384 KB Output is correct
36 Correct 1107 ms 124964 KB Output is correct
37 Correct 1214 ms 134772 KB Output is correct
38 Correct 7 ms 14420 KB Output is correct
39 Correct 7 ms 14420 KB Output is correct
40 Correct 9 ms 14676 KB Output is correct
41 Correct 18 ms 15460 KB Output is correct
42 Correct 71 ms 45392 KB Output is correct
43 Correct 61 ms 42512 KB Output is correct
44 Correct 64 ms 42740 KB Output is correct
45 Correct 7 ms 14420 KB Output is correct
46 Correct 60 ms 42516 KB Output is correct
47 Correct 58 ms 42616 KB Output is correct
48 Correct 65 ms 42532 KB Output is correct
49 Correct 60 ms 42508 KB Output is correct
50 Correct 59 ms 42812 KB Output is correct
51 Correct 68 ms 42696 KB Output is correct
52 Correct 62 ms 42564 KB Output is correct
53 Execution timed out 6061 ms 197940 KB Time limit exceeded
54 Halted 0 ms 0 KB -

Subtask #7
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 15700 KB Output is correct
2 Correct 66 ms 45768 KB Output is correct
3 Correct 63 ms 42784 KB Output is correct
4 Correct 62 ms 42984 KB Output is correct
5 Correct 7 ms 14432 KB Output is correct
6 Correct 61 ms 42888 KB Output is correct
7 Correct 18 ms 15712 KB Output is correct
8 Correct 67 ms 45744 KB Output is correct
9 Correct 68 ms 42848 KB Output is correct
10 Correct 60 ms 43020 KB Output is correct
11 Correct 8 ms 14432 KB Output is correct
12 Correct 61 ms 42844 KB Output is correct
13 Correct 59 ms 42872 KB Output is correct
14 Correct 61 ms 42808 KB Output is correct
15 Correct 76 ms 42828 KB Output is correct
16 Correct 62 ms 43040 KB Output is correct
17 Correct 62 ms 42856 KB Output is correct
18 Correct 64 ms 42772 KB Output is correct
19 Correct 17 ms 15732 KB Output is correct
20 Correct 74 ms 45700 KB Output is correct
21 Correct 65 ms 42880 KB Output is correct
22 Correct 79 ms 42916 KB Output is correct
23 Correct 8 ms 14388 KB Output is correct
24 Correct 64 ms 42792 KB Output is correct
25 Correct 72 ms 42992 KB Output is correct
26 Correct 63 ms 42888 KB Output is correct
27 Correct 58 ms 42772 KB Output is correct
28 Correct 61 ms 42984 KB Output is correct
29 Correct 62 ms 42828 KB Output is correct
30 Correct 66 ms 42868 KB Output is correct
31 Correct 1162 ms 128220 KB Output is correct
32 Correct 1042 ms 134648 KB Output is correct
33 Correct 1077 ms 127612 KB Output is correct
34 Correct 903 ms 132400 KB Output is correct
35 Correct 1086 ms 121384 KB Output is correct
36 Correct 1107 ms 124964 KB Output is correct
37 Correct 1214 ms 134772 KB Output is correct
38 Correct 18 ms 15444 KB Output is correct
39 Correct 61 ms 45476 KB Output is correct
40 Correct 64 ms 42572 KB Output is correct
41 Correct 64 ms 42676 KB Output is correct
42 Correct 7 ms 14420 KB Output is correct
43 Correct 71 ms 42644 KB Output is correct
44 Correct 64 ms 42612 KB Output is correct
45 Correct 63 ms 42620 KB Output is correct
46 Correct 62 ms 42520 KB Output is correct
47 Correct 59 ms 42828 KB Output is correct
48 Correct 61 ms 42700 KB Output is correct
49 Correct 75 ms 42608 KB Output is correct
50 Correct 1110 ms 127844 KB Output is correct
51 Correct 966 ms 134260 KB Output is correct
52 Correct 929 ms 127596 KB Output is correct
53 Correct 775 ms 132460 KB Output is correct
54 Correct 1156 ms 121404 KB Output is correct
55 Correct 1084 ms 124988 KB Output is correct
56 Correct 1221 ms 134660 KB Output is correct
57 Correct 971 ms 128572 KB Output is correct
58 Correct 918 ms 135152 KB Output is correct
59 Correct 927 ms 127408 KB Output is correct
60 Correct 774 ms 121108 KB Output is correct
61 Correct 1137 ms 127292 KB Output is correct
62 Correct 1198 ms 121052 KB Output is correct
63 Correct 7 ms 14420 KB Output is correct
64 Correct 7 ms 14420 KB Output is correct
65 Correct 9 ms 14676 KB Output is correct
66 Correct 18 ms 15460 KB Output is correct
67 Correct 71 ms 45392 KB Output is correct
68 Correct 61 ms 42512 KB Output is correct
69 Correct 64 ms 42740 KB Output is correct
70 Correct 7 ms 14420 KB Output is correct
71 Correct 60 ms 42516 KB Output is correct
72 Correct 58 ms 42616 KB Output is correct
73 Correct 65 ms 42532 KB Output is correct
74 Correct 60 ms 42508 KB Output is correct
75 Correct 59 ms 42812 KB Output is correct
76 Correct 68 ms 42696 KB Output is correct
77 Correct 62 ms 42564 KB Output is correct
78 Execution timed out 6061 ms 197940 KB Time limit exceeded
79 Halted 0 ms 0 KB -