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답안 #469287

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
469287 2021-08-31T11:00:34 Z sinamhdv LOSTIKS (INOI20_lostiks) C++11
100 / 100
 1276 ms 258364 KB 
#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
const int mod = 1000 * 1000 * 1000 + 7;
const int INF = 1e9 + 100;
const ll LINF = 1e18 + 100;

#ifdef DEBUG
#define dbg(x) cout << #x << " = " << (x) << endl << flush;
#define dbgr(s, f) { cout << #s << ": "; for (auto _ = (s); _ != (f); _++) cout << *_ << ' '; cout << endl << flush; }
#else
#define dbg(x) ;
#define dbgr(s, f) ;
#endif
#define fast_io ios::sync_with_stdio(0); cin.tie(0);
#define FOR(i, a, b) for (int i = (a); i < (b); i++)
#define all(x) (x).begin(), (x).end()
#define pb push_back
#define fr first
#define sc second
#define endl '\n'

const int MAXN = 1000010;
const int MAXE = 22;
const int LOGN = 21;

int n, s, t, m;
int ef[MAXN], eto[MAXN], ky[MAXN], kind[MAXN];
vector<int> adj[MAXN];
vector<int> lpar[LOGN];
int h[MAXN];
int pth[MAXN];
int lck[MAXE];
vector<int> dp[1 << 20];
int inp[MAXE];
int cost[MAXE][MAXE];
int tot;
int ldis[MAXE];

void dfs(int v)
{
	for (int e : adj[v])
	{
		int u = ef[e] ^ eto[e] ^ v;
		if (u == lpar[0][v]) continue;
		lpar[0][u] = v;
		h[u] = h[v] + 1;
		pth[u] = pth[v] | (ky[e] ? (1 << kind[e]) : 0);
		dfs(u);
	}
}

void bkdfs(int v)
{
	tot |= (1 << v);
	FOR(i, 0, m) if ((inp[v] >> i & 1) && !(tot >> i & 1)) bkdfs(i);
}

inline int getpar(int x, int d)
{
	FOR(i, 0, LOGN) if (d >> i & 1) x = lpar[i][x];
	return x;
}

inline int getlca(int x, int y)
{
	if (h[x] > h[y]) swap(x, y);
	y = getpar(y, h[y] - h[x]);
	if (x == y) return x;
	for (int i = LOGN - 1; i >= 0; i--)
	{
		if (lpar[i][x] != lpar[i][y])
		{
			x = lpar[i][x];
			y = lpar[i][y];
		}
	}
	return lpar[0][x];
}

int32_t main(void)
{
	fast_io;
	cin >> n >> s >> t;
	FOR(i, 0, n - 1)
	{
		cin >> ef[i] >> eto[i] >> ky[i];
		adj[ef[i]].pb(i);
		adj[eto[i]].pb(i);
		if (ky[i])
		{
			lck[m] = i;
			kind[i] = m;
			m++;
		}
	}

	dbg(m);

	FOR(i, 0, LOGN) lpar[i].resize(n + 5);
	dfs(s);

	dbgr(pth + 1, pth + n + 1);
	if (pth[t] == 0)
	{
		return cout << h[t] << endl, 0;
	}

	FOR(i, 0, n - 1) if (h[ef[i]] > h[eto[i]]) swap(ef[i], eto[i]);

	FOR(i, 1, LOGN) FOR(j, 1, n + 1) lpar[i][j] = lpar[i - 1][lpar[i - 1][j]];

	FOR(i, 0, m)
	{
		int e = lck[i];
		inp[i] = (pth[ef[e]] | pth[ky[e]]);
	}

	FOR(i, 0, m) FOR(j, 0, m) if (i != j)
	{
		int x = ef[lck[i]];
		int y = ky[lck[j]];
		int z = ef[lck[j]];
		cost[i][j] = h[x] + h[y] - 2 * h[getlca(x, y)] + h[y] + h[z] - 2 * h[getlca(y, z)];

//		cout << i << ' ' << j << ' ' << cost[i][j] << endl;
	}


	FOR(i, 0, m)
	{
		ldis[i] = h[ef[lck[i]]] + h[ky[lck[i]]] - 2 * h[getlca(ef[lck[i]], ky[lck[i]])];
	}

	FOR(i, 0, LOGN)
	{
		lpar[i].clear();
		lpar[i].shrink_to_fit();
	}

	dbgr(h + 1, h + n + 1);
	dbgr(pth + 1, pth + n + 1);
	dbgr(lck, lck + m);
	dbgr(inp, inp + m);

	FOR(mask, 0, 1 << m) dp[mask].resize(m, INF);
	fill(all(dp[0]), 0);
//	FOR(mask, 1, 1 << m) fill(dp[mask], dp[mask] + m, INF);

	FOR(mask, 1, 1 << m)
	{
		if (__builtin_popcount(mask) == 1)
		{
			int v = __lg(mask);
			if (!(inp[v] & mask)) dp[mask][v] = 0;
			continue;
		}
		FOR(v, 0, m)
		{
			if ((mask >> v & 1) && (inp[v] & mask) == 0)
			{
				int sub = mask ^ (1 << v);
				FOR(x, 0, m) if (sub >> x & 1)
				{
					dp[mask][v] = min(dp[mask][v], dp[sub][x] + cost[v][x]);
				}
			}
		}
	}

//	FOR(mask, 0, 1 << m) FOR(v, 0, m) cout << v << ' ' << mask << ' ' << dp[mask][v] << endl;

	int laste = -1;
	FOR(i, 0, m) if (pth[t] >> i & 1) if (laste == -1 || h[ef[lck[i]]] > h[ef[lck[laste]]]) laste = i;

	bkdfs(laste);
	int ans = INF;
	FOR(v, 0, m)
	{
		int cs = h[ky[lck[v]]] + ldis[v]; //h[ky[lck[v]]] + h[ef[lck[v]]] - 2 * h[getlca(ky[lck[v]], ef[lck[v]])];
		ans = min(ans, cs + dp[tot][v]);
	}

	if (ans >= INF) return cout << "-1\n", 0;
	ans += h[t] - h[ef[lck[laste]]];

	cout << ans << endl;

	return 0;
}

Subtask #1
23.0 / 23.0

# 결과 실행 시간 메모리 Grader output
1 Correct 26 ms 48460 KB Output is correct
2 Correct 26 ms 48460 KB Output is correct
3 Correct 87 ms 62000 KB Output is correct
4 Correct 85 ms 62016 KB Output is correct
5 Correct 86 ms 62020 KB Output is correct
6 Correct 89 ms 62192 KB Output is correct
7 Correct 85 ms 62088 KB Output is correct
8 Correct 86 ms 62148 KB Output is correct
9 Correct 85 ms 62268 KB Output is correct
10 Correct 85 ms 62096 KB Output is correct
11 Correct 88 ms 62148 KB Output is correct
12 Correct 83 ms 64068 KB Output is correct
13 Correct 82 ms 63596 KB Output is correct
14 Correct 79 ms 63276 KB Output is correct
15 Correct 79 ms 64196 KB Output is correct
16 Correct 82 ms 64872 KB Output is correct
17 Correct 87 ms 64972 KB Output is correct
18 Correct 91 ms 65372 KB Output is correct
19 Correct 84 ms 69436 KB Output is correct
20 Correct 88 ms 69284 KB Output is correct
21 Correct 85 ms 69144 KB Output is correct
22 Correct 26 ms 48460 KB Output is correct
23 Correct 25 ms 48468 KB Output is correct
24 Correct 26 ms 48388 KB Output is correct
25 Correct 30 ms 48392 KB Output is correct
26 Correct 27 ms 48460 KB Output is correct

Subtask #2
36.0 / 36.0

# 결과 실행 시간 메모리 Grader output
1 Correct 26 ms 48352 KB Output is correct
2 Correct 27 ms 48396 KB Output is correct
3 Correct 26 ms 48532 KB Output is correct
4 Correct 27 ms 48512 KB Output is correct
5 Correct 210 ms 98068 KB Output is correct
6 Correct 180 ms 98180 KB Output is correct
7 Correct 232 ms 98096 KB Output is correct
8 Correct 191 ms 98056 KB Output is correct
9 Correct 208 ms 98052 KB Output is correct
10 Correct 146 ms 98052 KB Output is correct
11 Correct 145 ms 98072 KB Output is correct
12 Correct 146 ms 98040 KB Output is correct
13 Correct 152 ms 98044 KB Output is correct
14 Correct 156 ms 98048 KB Output is correct
15 Correct 198 ms 98096 KB Output is correct
16 Correct 228 ms 98056 KB Output is correct
17 Correct 201 ms 98220 KB Output is correct
18 Correct 145 ms 98184 KB Output is correct
19 Correct 148 ms 98180 KB Output is correct
20 Correct 147 ms 98180 KB Output is correct
21 Correct 151 ms 98400 KB Output is correct
22 Correct 146 ms 98564 KB Output is correct
23 Correct 147 ms 98640 KB Output is correct
24 Correct 148 ms 98616 KB Output is correct
25 Correct 932 ms 147020 KB Output is correct

Subtask #3
41.0 / 41.0

# 결과 실행 시간 메모리 Grader output
1 Correct 26 ms 48460 KB Output is correct
2 Correct 26 ms 48460 KB Output is correct
3 Correct 87 ms 62000 KB Output is correct
4 Correct 85 ms 62016 KB Output is correct
5 Correct 86 ms 62020 KB Output is correct
6 Correct 89 ms 62192 KB Output is correct
7 Correct 85 ms 62088 KB Output is correct
8 Correct 86 ms 62148 KB Output is correct
9 Correct 85 ms 62268 KB Output is correct
10 Correct 85 ms 62096 KB Output is correct
11 Correct 88 ms 62148 KB Output is correct
12 Correct 83 ms 64068 KB Output is correct
13 Correct 82 ms 63596 KB Output is correct
14 Correct 79 ms 63276 KB Output is correct
15 Correct 79 ms 64196 KB Output is correct
16 Correct 82 ms 64872 KB Output is correct
17 Correct 87 ms 64972 KB Output is correct
18 Correct 91 ms 65372 KB Output is correct
19 Correct 84 ms 69436 KB Output is correct
20 Correct 88 ms 69284 KB Output is correct
21 Correct 85 ms 69144 KB Output is correct
22 Correct 26 ms 48460 KB Output is correct
23 Correct 25 ms 48468 KB Output is correct
24 Correct 26 ms 48388 KB Output is correct
25 Correct 30 ms 48392 KB Output is correct
26 Correct 27 ms 48460 KB Output is correct
27 Correct 26 ms 48352 KB Output is correct
28 Correct 27 ms 48396 KB Output is correct
29 Correct 26 ms 48532 KB Output is correct
30 Correct 27 ms 48512 KB Output is correct
31 Correct 210 ms 98068 KB Output is correct
32 Correct 180 ms 98180 KB Output is correct
33 Correct 232 ms 98096 KB Output is correct
34 Correct 191 ms 98056 KB Output is correct
35 Correct 208 ms 98052 KB Output is correct
36 Correct 146 ms 98052 KB Output is correct
37 Correct 145 ms 98072 KB Output is correct
38 Correct 146 ms 98040 KB Output is correct
39 Correct 152 ms 98044 KB Output is correct
40 Correct 156 ms 98048 KB Output is correct
41 Correct 198 ms 98096 KB Output is correct
42 Correct 228 ms 98056 KB Output is correct
43 Correct 201 ms 98220 KB Output is correct
44 Correct 145 ms 98184 KB Output is correct
45 Correct 148 ms 98180 KB Output is correct
46 Correct 147 ms 98180 KB Output is correct
47 Correct 151 ms 98400 KB Output is correct
48 Correct 146 ms 98564 KB Output is correct
49 Correct 147 ms 98640 KB Output is correct
50 Correct 148 ms 98616 KB Output is correct
51 Correct 932 ms 147020 KB Output is correct
52 Correct 1218 ms 188388 KB Output is correct
53 Correct 1208 ms 188352 KB Output is correct
54 Correct 1195 ms 185964 KB Output is correct
55 Correct 1220 ms 185580 KB Output is correct
56 Correct 1206 ms 186564 KB Output is correct
57 Correct 1191 ms 188100 KB Output is correct
58 Correct 27 ms 48460 KB Output is correct
59 Correct 28 ms 48560 KB Output is correct
60 Correct 26 ms 48396 KB Output is correct
61 Correct 1227 ms 188524 KB Output is correct
62 Correct 1276 ms 185412 KB Output is correct
63 Correct 1211 ms 185400 KB Output is correct
64 Correct 97 ms 63940 KB Output is correct
65 Correct 98 ms 64476 KB Output is correct
66 Correct 1220 ms 188700 KB Output is correct
67 Correct 1218 ms 188296 KB Output is correct
68 Correct 1091 ms 183840 KB Output is correct
69 Correct 1086 ms 184120 KB Output is correct
70 Correct 1104 ms 183432 KB Output is correct
71 Correct 1136 ms 183492 KB Output is correct
72 Correct 1088 ms 183444 KB Output is correct
73 Correct 1042 ms 185040 KB Output is correct
74 Correct 1085 ms 185900 KB Output is correct
75 Correct 1091 ms 185668 KB Output is correct
76 Correct 1056 ms 186564 KB Output is correct
77 Correct 1065 ms 185200 KB Output is correct
78 Correct 1045 ms 193140 KB Output is correct
79 Correct 1059 ms 192840 KB Output is correct
80 Correct 1027 ms 191376 KB Output is correct
81 Correct 967 ms 207720 KB Output is correct
82 Correct 995 ms 209324 KB Output is correct
83 Correct 1006 ms 209260 KB Output is correct
84 Correct 987 ms 220520 KB Output is correct
85 Correct 1014 ms 258364 KB Output is correct
86 Correct 1016 ms 257092 KB Output is correct
87 Correct 1042 ms 257184 KB Output is correct