oj.uz

답안 #635426

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
635426 2022-08-26T08:45:16 Z S2speed LOSTIKS (INOI20_lostiks) C++17
59 / 100
 2000 ms 251228 KB 
#include<bits/stdc++.h>

using namespace std;

#pragma GCC optimize ("Ofast")

#define sze(x) (int)(x.size())
typedef long long ll;
typedef pair<ll , ll> pll;
typedef pair<int , int> pii;

const ll maxn = (1 << 20) + 17 , inf = 2e8;

int n , s , t;
vector<pii> adj[maxn];
int dis[22][maxn];
int bfs[maxn] , sz = 0;
int g[maxn] , k[22] , d[22] , e[22] , f[22][22] , dp[maxn][22];

void BFS(int r , int h , bool f = false){
	sz = 0;
	dis[h][r] = 0;
	g[r] = 0;
	bfs[sz++] = r;
	int x = 0;
	while(x < sz){
		int v = bfs[x++];
		for(auto p : adj[v]){
			int i = p.first , t = p.second;
			if(dis[h][i] < dis[h][v] + 1) continue;
			if(f){
				g[i] = g[v];
				if(t != -1){
					g[i] ^= (1 << t);
					d[t] = v;
				}
			}
			dis[h][i] = dis[h][v] + 1;
			bfs[sz++] = i;
		}
	}
	return;
}

int main(){
	ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);

	memset(dp , 63 , sizeof(dp));
	memset(dis , 63 , sizeof(dis));
	cin>>n>>s>>t; s--; t--;
	int m = 0;
	for(int i = 1 ; i < n ; i++){
		int v , u , w;
		cin>>v>>u>>w; v--; u--; w--;
		if(w != -1){
			k[m] = w;
			adj[v].push_back({u , m}); adj[u].push_back({v , m});
			m++;
		} else {
			adj[v].push_back({u , w}); adj[u].push_back({v , w});
		}
	}
	BFS(s , m , true);
	if(g[t] == 0){
		cout<<dis[m][t]<<'\n';
		return 0;
	}
	for(int j = 0 ; j < m ; j++){
		e[j] = g[k[j]] | g[d[j]];
		BFS(d[j] , j);
		if(e[j] == 0){
			dp[(1 << j)][j] = dis[m][k[j]] + dis[j][k[j]];
		}
	}
	for(int i = 0 ; i < m ; i++){
		for(int j = 0 ; j < m ; j++){
			f[i][j] = dis[i][k[j]] + dis[j][k[j]];
		}
	}
	int lm = (1 << m);
	for(int mask = 1 ; mask < lm ; mask++){
		for(int j = 0 ; j < m ; j++){
			if(mask & (1 << j)) continue;
			if((e[j] & mask) != e[j]) continue;
			int h = inf;
			for(int i = 0 ; i < m ; i++){
				if(!(mask & (1 << i))) continue;
				h = min(h , dp[mask][i] + f[i][j]);
			}
			dp[mask ^ (1 << j)][j] = min(dp[mask ^ (1 << j)][j] , h);
		}
	}
	int ans = inf;
	for(int mask = 1 ; mask < lm ; mask++){
		if((g[t] & mask) != g[t]) continue;
		int h = inf;
		for(int i = 0 ; i < m ; i++){
			if(!(mask & (1 << i))) continue;
//			cout<<mask<<' '<<i<<'\n';
			h = min(h , dp[mask][i] + dis[i][t]);
		}
		ans = min(ans , h);
	}
	cout<<(ans == inf ? -1 : ans)<<'\n';
	return 0;
}

Subtask #1
23.0 / 23.0

# 결과 실행 시간 메모리 Grader output
1 Correct 78 ms 205516 KB Output is correct
2 Correct 78 ms 205448 KB Output is correct
3 Correct 138 ms 210044 KB Output is correct
4 Correct 135 ms 210016 KB Output is correct
5 Correct 135 ms 210032 KB Output is correct
6 Correct 141 ms 209944 KB Output is correct
7 Correct 144 ms 209996 KB Output is correct
8 Correct 139 ms 209952 KB Output is correct
9 Correct 133 ms 209964 KB Output is correct
10 Correct 137 ms 209924 KB Output is correct
11 Correct 149 ms 210036 KB Output is correct
12 Correct 158 ms 209408 KB Output is correct
13 Correct 133 ms 209436 KB Output is correct
14 Correct 145 ms 209348 KB Output is correct
15 Correct 156 ms 209356 KB Output is correct
16 Correct 134 ms 209420 KB Output is correct
17 Correct 138 ms 209396 KB Output is correct
18 Correct 141 ms 209348 KB Output is correct
19 Correct 139 ms 209416 KB Output is correct
20 Correct 137 ms 209356 KB Output is correct
21 Correct 128 ms 209352 KB Output is correct
22 Correct 82 ms 205468 KB Output is correct
23 Correct 76 ms 205516 KB Output is correct
24 Correct 79 ms 205488 KB Output is correct
25 Correct 80 ms 205416 KB Output is correct
26 Correct 76 ms 205464 KB Output is correct

Subtask #2
36.0 / 36.0

# 결과 실행 시간 메모리 Grader output
1 Correct 77 ms 205516 KB Output is correct
2 Correct 80 ms 205424 KB Output is correct
3 Correct 77 ms 205448 KB Output is correct
4 Correct 79 ms 205500 KB Output is correct
5 Correct 192 ms 205836 KB Output is correct
6 Correct 183 ms 205780 KB Output is correct
7 Correct 208 ms 205900 KB Output is correct
8 Correct 168 ms 205788 KB Output is correct
9 Correct 219 ms 205816 KB Output is correct
10 Correct 135 ms 205796 KB Output is correct
11 Correct 138 ms 205772 KB Output is correct
12 Correct 149 ms 205844 KB Output is correct
13 Correct 144 ms 205844 KB Output is correct
14 Correct 144 ms 205804 KB Output is correct
15 Correct 170 ms 205736 KB Output is correct
16 Correct 195 ms 205772 KB Output is correct
17 Correct 187 ms 205776 KB Output is correct
18 Correct 143 ms 205800 KB Output is correct
19 Correct 136 ms 205760 KB Output is correct
20 Correct 136 ms 205804 KB Output is correct
21 Correct 145 ms 205792 KB Output is correct
22 Correct 137 ms 205800 KB Output is correct
23 Correct 132 ms 205772 KB Output is correct
24 Correct 132 ms 205700 KB Output is correct
25 Correct 639 ms 205572 KB Output is correct

Subtask #3
0 / 41.0

# 결과 실행 시간 메모리 Grader output
1 Correct 78 ms 205516 KB Output is correct
2 Correct 78 ms 205448 KB Output is correct
3 Correct 138 ms 210044 KB Output is correct
4 Correct 135 ms 210016 KB Output is correct
5 Correct 135 ms 210032 KB Output is correct
6 Correct 141 ms 209944 KB Output is correct
7 Correct 144 ms 209996 KB Output is correct
8 Correct 139 ms 209952 KB Output is correct
9 Correct 133 ms 209964 KB Output is correct
10 Correct 137 ms 209924 KB Output is correct
11 Correct 149 ms 210036 KB Output is correct
12 Correct 158 ms 209408 KB Output is correct
13 Correct 133 ms 209436 KB Output is correct
14 Correct 145 ms 209348 KB Output is correct
15 Correct 156 ms 209356 KB Output is correct
16 Correct 134 ms 209420 KB Output is correct
17 Correct 138 ms 209396 KB Output is correct
18 Correct 141 ms 209348 KB Output is correct
19 Correct 139 ms 209416 KB Output is correct
20 Correct 137 ms 209356 KB Output is correct
21 Correct 128 ms 209352 KB Output is correct
22 Correct 82 ms 205468 KB Output is correct
23 Correct 76 ms 205516 KB Output is correct
24 Correct 79 ms 205488 KB Output is correct
25 Correct 80 ms 205416 KB Output is correct
26 Correct 76 ms 205464 KB Output is correct
27 Correct 77 ms 205516 KB Output is correct
28 Correct 80 ms 205424 KB Output is correct
29 Correct 77 ms 205448 KB Output is correct
30 Correct 79 ms 205500 KB Output is correct
31 Correct 192 ms 205836 KB Output is correct
32 Correct 183 ms 205780 KB Output is correct
33 Correct 208 ms 205900 KB Output is correct
34 Correct 168 ms 205788 KB Output is correct
35 Correct 219 ms 205816 KB Output is correct
36 Correct 135 ms 205796 KB Output is correct
37 Correct 138 ms 205772 KB Output is correct
38 Correct 149 ms 205844 KB Output is correct
39 Correct 144 ms 205844 KB Output is correct
40 Correct 144 ms 205804 KB Output is correct
41 Correct 170 ms 205736 KB Output is correct
42 Correct 195 ms 205772 KB Output is correct
43 Correct 187 ms 205776 KB Output is correct
44 Correct 143 ms 205800 KB Output is correct
45 Correct 136 ms 205760 KB Output is correct
46 Correct 136 ms 205804 KB Output is correct
47 Correct 145 ms 205792 KB Output is correct
48 Correct 137 ms 205800 KB Output is correct
49 Correct 132 ms 205772 KB Output is correct
50 Correct 132 ms 205700 KB Output is correct
51 Correct 639 ms 205572 KB Output is correct
52 Correct 1767 ms 250928 KB Output is correct
53 Execution timed out 2047 ms 251228 KB Time limit exceeded
54 Halted 0 ms 0 KB -