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답안 #635427

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
635427 2022-08-26T08:53:41 Z S2speed LOSTIKS (INOI20_lostiks) C++17
59 / 100
 2000 ms 250868 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] , ind[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 = 3 ; mask < lm ; mask++){
		int bp = 0;
		for(int j = 0 ; j < m ; j++){
			if(mask & (1 << j)) ind[bp++] = j;
		}
		if(bp == 1) continue;
		for(int jj = 0 ; jj < bp ; jj++){
			int j = ind[jj];
			if((e[j] & mask) != e[j]) continue;
			int h = inf , msk = mask ^ (1 << j);
			for(int ii = 0 ; ii < bp ; ii++){
				int i = ind[ii];
				if(i == j) continue;
				h = min(h , dp[msk][i] + f[i][j]);
			}
			dp[mask][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 83 ms 205496 KB Output is correct
2 Correct 86 ms 205492 KB Output is correct
3 Correct 140 ms 210060 KB Output is correct
4 Correct 147 ms 210016 KB Output is correct
5 Correct 149 ms 210000 KB Output is correct
6 Correct 153 ms 209980 KB Output is correct
7 Correct 143 ms 209948 KB Output is correct
8 Correct 137 ms 210116 KB Output is correct
9 Correct 138 ms 209984 KB Output is correct
10 Correct 133 ms 210032 KB Output is correct
11 Correct 157 ms 210048 KB Output is correct
12 Correct 143 ms 209436 KB Output is correct
13 Correct 137 ms 209352 KB Output is correct
14 Correct 130 ms 209356 KB Output is correct
15 Correct 147 ms 209368 KB Output is correct
16 Correct 143 ms 209336 KB Output is correct
17 Correct 126 ms 209360 KB Output is correct
18 Correct 124 ms 209372 KB Output is correct
19 Correct 129 ms 209436 KB Output is correct
20 Correct 130 ms 209424 KB Output is correct
21 Correct 129 ms 209448 KB Output is correct
22 Correct 75 ms 205524 KB Output is correct
23 Correct 76 ms 205432 KB Output is correct
24 Correct 78 ms 205448 KB Output is correct
25 Correct 83 ms 205412 KB Output is correct
26 Correct 80 ms 205480 KB Output is correct

Subtask #2
36.0 / 36.0

# 결과 실행 시간 메모리 Grader output
1 Correct 77 ms 205520 KB Output is correct
2 Correct 74 ms 205448 KB Output is correct
3 Correct 78 ms 205496 KB Output is correct
4 Correct 92 ms 205408 KB Output is correct
5 Correct 172 ms 205836 KB Output is correct
6 Correct 146 ms 205836 KB Output is correct
7 Correct 188 ms 205840 KB Output is correct
8 Correct 151 ms 205772 KB Output is correct
9 Correct 159 ms 205840 KB Output is correct
10 Correct 127 ms 205824 KB Output is correct
11 Correct 129 ms 205840 KB Output is correct
12 Correct 129 ms 205764 KB Output is correct
13 Correct 132 ms 205900 KB Output is correct
14 Correct 128 ms 205744 KB Output is correct
15 Correct 147 ms 205884 KB Output is correct
16 Correct 160 ms 205688 KB Output is correct
17 Correct 162 ms 205732 KB Output is correct
18 Correct 125 ms 205684 KB Output is correct
19 Correct 136 ms 205732 KB Output is correct
20 Correct 129 ms 205728 KB Output is correct
21 Correct 126 ms 205728 KB Output is correct
22 Correct 126 ms 205796 KB Output is correct
23 Correct 126 ms 205892 KB Output is correct
24 Correct 129 ms 205712 KB Output is correct
25 Correct 361 ms 205460 KB Output is correct

Subtask #3
0 / 41.0

# 결과 실행 시간 메모리 Grader output
1 Correct 83 ms 205496 KB Output is correct
2 Correct 86 ms 205492 KB Output is correct
3 Correct 140 ms 210060 KB Output is correct
4 Correct 147 ms 210016 KB Output is correct
5 Correct 149 ms 210000 KB Output is correct
6 Correct 153 ms 209980 KB Output is correct
7 Correct 143 ms 209948 KB Output is correct
8 Correct 137 ms 210116 KB Output is correct
9 Correct 138 ms 209984 KB Output is correct
10 Correct 133 ms 210032 KB Output is correct
11 Correct 157 ms 210048 KB Output is correct
12 Correct 143 ms 209436 KB Output is correct
13 Correct 137 ms 209352 KB Output is correct
14 Correct 130 ms 209356 KB Output is correct
15 Correct 147 ms 209368 KB Output is correct
16 Correct 143 ms 209336 KB Output is correct
17 Correct 126 ms 209360 KB Output is correct
18 Correct 124 ms 209372 KB Output is correct
19 Correct 129 ms 209436 KB Output is correct
20 Correct 130 ms 209424 KB Output is correct
21 Correct 129 ms 209448 KB Output is correct
22 Correct 75 ms 205524 KB Output is correct
23 Correct 76 ms 205432 KB Output is correct
24 Correct 78 ms 205448 KB Output is correct
25 Correct 83 ms 205412 KB Output is correct
26 Correct 80 ms 205480 KB Output is correct
27 Correct 77 ms 205520 KB Output is correct
28 Correct 74 ms 205448 KB Output is correct
29 Correct 78 ms 205496 KB Output is correct
30 Correct 92 ms 205408 KB Output is correct
31 Correct 172 ms 205836 KB Output is correct
32 Correct 146 ms 205836 KB Output is correct
33 Correct 188 ms 205840 KB Output is correct
34 Correct 151 ms 205772 KB Output is correct
35 Correct 159 ms 205840 KB Output is correct
36 Correct 127 ms 205824 KB Output is correct
37 Correct 129 ms 205840 KB Output is correct
38 Correct 129 ms 205764 KB Output is correct
39 Correct 132 ms 205900 KB Output is correct
40 Correct 128 ms 205744 KB Output is correct
41 Correct 147 ms 205884 KB Output is correct
42 Correct 160 ms 205688 KB Output is correct
43 Correct 162 ms 205732 KB Output is correct
44 Correct 125 ms 205684 KB Output is correct
45 Correct 136 ms 205732 KB Output is correct
46 Correct 129 ms 205728 KB Output is correct
47 Correct 126 ms 205728 KB Output is correct
48 Correct 126 ms 205796 KB Output is correct
49 Correct 126 ms 205892 KB Output is correct
50 Correct 129 ms 205712 KB Output is correct
51 Correct 361 ms 205460 KB Output is correct
52 Correct 1845 ms 250868 KB Output is correct
53 Execution timed out 2102 ms 250724 KB Time limit exceeded
54 Halted 0 ms 0 KB -