oj.uz

Submission #817696

# Submission time Handle Problem Language Result Execution time Memory
817696 2023-08-09T15:06:25 Z MohamedAhmed04 From Hacks to Snitches (BOI21_watchmen) C++17
35 / 100
 6000 ms 311436 KB 
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")

#include <bits/stdc++.h>

using namespace std ;

const int inf = 1e9 ;
const int MAX = 3e5 + 10 ;
const int K = 50 ;

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][205] ;

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 < 205 ; ++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 71 ms 37888 KB Output is correct
3 Correct 66 ms 35816 KB Output is correct
4 Correct 59 ms 35988 KB Output is correct
5 Correct 7 ms 14436 KB Output is correct
6 Correct 65 ms 35752 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 15756 KB Output is correct
2 Correct 61 ms 37916 KB Output is correct
3 Correct 61 ms 35792 KB Output is correct
4 Correct 65 ms 35928 KB Output is correct
5 Correct 8 ms 14420 KB Output is correct
6 Correct 62 ms 35752 KB Output is correct
7 Correct 60 ms 35764 KB Output is correct
8 Correct 59 ms 35824 KB Output is correct
9 Correct 57 ms 35752 KB Output is correct
10 Correct 65 ms 36080 KB Output is correct
11 Correct 72 ms 35924 KB Output is correct
12 Correct 70 ms 35828 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 15756 KB Output is correct
2 Correct 61 ms 37916 KB Output is correct
3 Correct 61 ms 35792 KB Output is correct
4 Correct 65 ms 35928 KB Output is correct
5 Correct 8 ms 14420 KB Output is correct
6 Correct 62 ms 35752 KB Output is correct
7 Correct 60 ms 35764 KB Output is correct
8 Correct 59 ms 35824 KB Output is correct
9 Correct 57 ms 35752 KB Output is correct
10 Correct 65 ms 36080 KB Output is correct
11 Correct 72 ms 35924 KB Output is correct
12 Correct 70 ms 35828 KB Output is correct
13 Correct 19 ms 15668 KB Output is correct
14 Correct 62 ms 37964 KB Output is correct
15 Correct 57 ms 35832 KB Output is correct
16 Correct 73 ms 35936 KB Output is correct
17 Correct 8 ms 14420 KB Output is correct
18 Correct 59 ms 35788 KB Output is correct
19 Correct 61 ms 35768 KB Output is correct
20 Correct 57 ms 35820 KB Output is correct
21 Correct 62 ms 35824 KB Output is correct
22 Correct 57 ms 35916 KB Output is correct
23 Correct 58 ms 35848 KB Output is correct
24 Correct 57 ms 35812 KB Output is correct
25 Correct 1189 ms 108784 KB Output is correct
26 Correct 1041 ms 115188 KB Output is correct
27 Correct 892 ms 108516 KB Output is correct
28 Correct 845 ms 113368 KB Output is correct
29 Correct 1040 ms 102436 KB Output is correct
30 Correct 1024 ms 106032 KB Output is correct
31 Correct 1156 ms 115632 KB Output is correct

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 15756 KB Output is correct
2 Correct 61 ms 37916 KB Output is correct
3 Correct 61 ms 35792 KB Output is correct
4 Correct 65 ms 35928 KB Output is correct
5 Correct 8 ms 14420 KB Output is correct
6 Correct 62 ms 35752 KB Output is correct
7 Correct 60 ms 35764 KB Output is correct
8 Correct 59 ms 35824 KB Output is correct
9 Correct 57 ms 35752 KB Output is correct
10 Correct 65 ms 36080 KB Output is correct
11 Correct 72 ms 35924 KB Output is correct
12 Correct 70 ms 35828 KB Output is correct
13 Correct 19 ms 15668 KB Output is correct
14 Correct 62 ms 37964 KB Output is correct
15 Correct 57 ms 35832 KB Output is correct
16 Correct 73 ms 35936 KB Output is correct
17 Correct 8 ms 14420 KB Output is correct
18 Correct 59 ms 35788 KB Output is correct
19 Correct 61 ms 35768 KB Output is correct
20 Correct 57 ms 35820 KB Output is correct
21 Correct 62 ms 35824 KB Output is correct
22 Correct 57 ms 35916 KB Output is correct
23 Correct 58 ms 35848 KB Output is correct
24 Correct 57 ms 35812 KB Output is correct
25 Correct 1189 ms 108784 KB Output is correct
26 Correct 1041 ms 115188 KB Output is correct
27 Correct 892 ms 108516 KB Output is correct
28 Correct 845 ms 113368 KB Output is correct
29 Correct 1040 ms 102436 KB Output is correct
30 Correct 1024 ms 106032 KB Output is correct
31 Correct 1156 ms 115632 KB Output is correct
32 Correct 19 ms 15716 KB Output is correct
33 Correct 61 ms 37836 KB Output is correct
34 Correct 59 ms 35816 KB Output is correct
35 Correct 63 ms 35972 KB Output is correct
36 Correct 8 ms 14420 KB Output is correct
37 Correct 60 ms 35764 KB Output is correct
38 Correct 58 ms 35788 KB Output is correct
39 Correct 56 ms 35788 KB Output is correct
40 Correct 63 ms 35872 KB Output is correct
41 Correct 56 ms 36044 KB Output is correct
42 Correct 61 ms 35908 KB Output is correct
43 Correct 68 ms 35788 KB Output is correct
44 Correct 1067 ms 108856 KB Output is correct
45 Correct 932 ms 115152 KB Output is correct
46 Correct 821 ms 108528 KB Output is correct
47 Correct 794 ms 113412 KB Output is correct
48 Correct 1002 ms 102344 KB Output is correct
49 Correct 1045 ms 106024 KB Output is correct
50 Correct 1144 ms 115740 KB Output is correct
51 Correct 1010 ms 109648 KB Output is correct
52 Correct 1014 ms 116116 KB Output is correct
53 Correct 979 ms 108360 KB Output is correct
54 Correct 747 ms 102080 KB Output is correct
55 Correct 1160 ms 108256 KB Output is correct
56 Correct 1053 ms 101948 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 71 ms 37888 KB Output is correct
3 Correct 66 ms 35816 KB Output is correct
4 Correct 59 ms 35988 KB Output is correct
5 Correct 7 ms 14436 KB Output is correct
6 Correct 65 ms 35752 KB Output is correct
7 Correct 18 ms 15756 KB Output is correct
8 Correct 61 ms 37916 KB Output is correct
9 Correct 61 ms 35792 KB Output is correct
10 Correct 65 ms 35928 KB Output is correct
11 Correct 8 ms 14420 KB Output is correct
12 Correct 62 ms 35752 KB Output is correct
13 Correct 60 ms 35764 KB Output is correct
14 Correct 59 ms 35824 KB Output is correct
15 Correct 57 ms 35752 KB Output is correct
16 Correct 65 ms 36080 KB Output is correct
17 Correct 72 ms 35924 KB Output is correct
18 Correct 70 ms 35828 KB Output is correct
19 Correct 8 ms 14420 KB Output is correct
20 Correct 8 ms 14420 KB Output is correct
21 Correct 8 ms 15212 KB Output is correct
22 Correct 18 ms 15776 KB Output is correct
23 Correct 57 ms 38104 KB Output is correct
24 Correct 57 ms 36044 KB Output is correct
25 Correct 61 ms 36196 KB Output is correct
26 Correct 8 ms 14384 KB Output is correct
27 Correct 63 ms 36056 KB Output is correct
28 Correct 56 ms 36044 KB Output is correct
29 Correct 55 ms 36080 KB Output is correct
30 Correct 63 ms 36120 KB Output is correct
31 Correct 59 ms 36264 KB Output is correct
32 Correct 58 ms 36176 KB Output is correct
33 Correct 59 ms 36036 KB Output is correct
34 Correct 5572 ms 311436 KB Output is correct
35 Correct 5716 ms 310976 KB Output is correct
36 Execution timed out 6087 ms 311232 KB Time limit exceeded
37 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 71 ms 37888 KB Output is correct
3 Correct 66 ms 35816 KB Output is correct
4 Correct 59 ms 35988 KB Output is correct
5 Correct 7 ms 14436 KB Output is correct
6 Correct 65 ms 35752 KB Output is correct
7 Correct 18 ms 15756 KB Output is correct
8 Correct 61 ms 37916 KB Output is correct
9 Correct 61 ms 35792 KB Output is correct
10 Correct 65 ms 35928 KB Output is correct
11 Correct 8 ms 14420 KB Output is correct
12 Correct 62 ms 35752 KB Output is correct
13 Correct 60 ms 35764 KB Output is correct
14 Correct 59 ms 35824 KB Output is correct
15 Correct 57 ms 35752 KB Output is correct
16 Correct 65 ms 36080 KB Output is correct
17 Correct 72 ms 35924 KB Output is correct
18 Correct 70 ms 35828 KB Output is correct
19 Correct 19 ms 15668 KB Output is correct
20 Correct 62 ms 37964 KB Output is correct
21 Correct 57 ms 35832 KB Output is correct
22 Correct 73 ms 35936 KB Output is correct
23 Correct 8 ms 14420 KB Output is correct
24 Correct 59 ms 35788 KB Output is correct
25 Correct 61 ms 35768 KB Output is correct
26 Correct 57 ms 35820 KB Output is correct
27 Correct 62 ms 35824 KB Output is correct
28 Correct 57 ms 35916 KB Output is correct
29 Correct 58 ms 35848 KB Output is correct
30 Correct 57 ms 35812 KB Output is correct
31 Correct 1189 ms 108784 KB Output is correct
32 Correct 1041 ms 115188 KB Output is correct
33 Correct 892 ms 108516 KB Output is correct
34 Correct 845 ms 113368 KB Output is correct
35 Correct 1040 ms 102436 KB Output is correct
36 Correct 1024 ms 106032 KB Output is correct
37 Correct 1156 ms 115632 KB Output is correct
38 Correct 8 ms 14420 KB Output is correct
39 Correct 8 ms 14420 KB Output is correct
40 Correct 8 ms 15212 KB Output is correct
41 Correct 18 ms 15776 KB Output is correct
42 Correct 57 ms 38104 KB Output is correct
43 Correct 57 ms 36044 KB Output is correct
44 Correct 61 ms 36196 KB Output is correct
45 Correct 8 ms 14384 KB Output is correct
46 Correct 63 ms 36056 KB Output is correct
47 Correct 56 ms 36044 KB Output is correct
48 Correct 55 ms 36080 KB Output is correct
49 Correct 63 ms 36120 KB Output is correct
50 Correct 59 ms 36264 KB Output is correct
51 Correct 58 ms 36176 KB Output is correct
52 Correct 59 ms 36036 KB Output is correct
53 Correct 5572 ms 311436 KB Output is correct
54 Correct 5716 ms 310976 KB Output is correct
55 Execution timed out 6087 ms 311232 KB Time limit exceeded
56 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 71 ms 37888 KB Output is correct
3 Correct 66 ms 35816 KB Output is correct
4 Correct 59 ms 35988 KB Output is correct
5 Correct 7 ms 14436 KB Output is correct
6 Correct 65 ms 35752 KB Output is correct
7 Correct 18 ms 15756 KB Output is correct
8 Correct 61 ms 37916 KB Output is correct
9 Correct 61 ms 35792 KB Output is correct
10 Correct 65 ms 35928 KB Output is correct
11 Correct 8 ms 14420 KB Output is correct
12 Correct 62 ms 35752 KB Output is correct
13 Correct 60 ms 35764 KB Output is correct
14 Correct 59 ms 35824 KB Output is correct
15 Correct 57 ms 35752 KB Output is correct
16 Correct 65 ms 36080 KB Output is correct
17 Correct 72 ms 35924 KB Output is correct
18 Correct 70 ms 35828 KB Output is correct
19 Correct 19 ms 15668 KB Output is correct
20 Correct 62 ms 37964 KB Output is correct
21 Correct 57 ms 35832 KB Output is correct
22 Correct 73 ms 35936 KB Output is correct
23 Correct 8 ms 14420 KB Output is correct
24 Correct 59 ms 35788 KB Output is correct
25 Correct 61 ms 35768 KB Output is correct
26 Correct 57 ms 35820 KB Output is correct
27 Correct 62 ms 35824 KB Output is correct
28 Correct 57 ms 35916 KB Output is correct
29 Correct 58 ms 35848 KB Output is correct
30 Correct 57 ms 35812 KB Output is correct
31 Correct 1189 ms 108784 KB Output is correct
32 Correct 1041 ms 115188 KB Output is correct
33 Correct 892 ms 108516 KB Output is correct
34 Correct 845 ms 113368 KB Output is correct
35 Correct 1040 ms 102436 KB Output is correct
36 Correct 1024 ms 106032 KB Output is correct
37 Correct 1156 ms 115632 KB Output is correct
38 Correct 19 ms 15716 KB Output is correct
39 Correct 61 ms 37836 KB Output is correct
40 Correct 59 ms 35816 KB Output is correct
41 Correct 63 ms 35972 KB Output is correct
42 Correct 8 ms 14420 KB Output is correct
43 Correct 60 ms 35764 KB Output is correct
44 Correct 58 ms 35788 KB Output is correct
45 Correct 56 ms 35788 KB Output is correct
46 Correct 63 ms 35872 KB Output is correct
47 Correct 56 ms 36044 KB Output is correct
48 Correct 61 ms 35908 KB Output is correct
49 Correct 68 ms 35788 KB Output is correct
50 Correct 1067 ms 108856 KB Output is correct
51 Correct 932 ms 115152 KB Output is correct
52 Correct 821 ms 108528 KB Output is correct
53 Correct 794 ms 113412 KB Output is correct
54 Correct 1002 ms 102344 KB Output is correct
55 Correct 1045 ms 106024 KB Output is correct
56 Correct 1144 ms 115740 KB Output is correct
57 Correct 1010 ms 109648 KB Output is correct
58 Correct 1014 ms 116116 KB Output is correct
59 Correct 979 ms 108360 KB Output is correct
60 Correct 747 ms 102080 KB Output is correct
61 Correct 1160 ms 108256 KB Output is correct
62 Correct 1053 ms 101948 KB Output is correct
63 Correct 8 ms 14420 KB Output is correct
64 Correct 8 ms 14420 KB Output is correct
65 Correct 8 ms 15212 KB Output is correct
66 Correct 18 ms 15776 KB Output is correct
67 Correct 57 ms 38104 KB Output is correct
68 Correct 57 ms 36044 KB Output is correct
69 Correct 61 ms 36196 KB Output is correct
70 Correct 8 ms 14384 KB Output is correct
71 Correct 63 ms 36056 KB Output is correct
72 Correct 56 ms 36044 KB Output is correct
73 Correct 55 ms 36080 KB Output is correct
74 Correct 63 ms 36120 KB Output is correct
75 Correct 59 ms 36264 KB Output is correct
76 Correct 58 ms 36176 KB Output is correct
77 Correct 59 ms 36036 KB Output is correct
78 Correct 5572 ms 311436 KB Output is correct
79 Correct 5716 ms 310976 KB Output is correct
80 Execution timed out 6087 ms 311232 KB Time limit exceeded
81 Halted 0 ms 0 KB -