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답안 #469282

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
469282 2021-08-31T10:48:43 Z sinamhdv LOSTIKS (INOI20_lostiks) C++11
100 / 100
 1223 ms 274572 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];
int lpar[LOGN][MAXN];
int h[MAXN];
int pth[MAXN];
int lck[MAXE];
int dp[1 << 20][20];
int inp[MAXE];
int cost[MAXE][MAXE];
int tot;

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);

	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;
	}

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

	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]]] + 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 13 ms 24012 KB Output is correct
2 Correct 13 ms 23956 KB Output is correct
3 Correct 69 ms 37496 KB Output is correct
4 Correct 73 ms 37564 KB Output is correct
5 Correct 76 ms 37552 KB Output is correct
6 Correct 91 ms 37620 KB Output is correct
7 Correct 73 ms 37652 KB Output is correct
8 Correct 72 ms 37688 KB Output is correct
9 Correct 73 ms 37804 KB Output is correct
10 Correct 72 ms 37604 KB Output is correct
11 Correct 87 ms 37680 KB Output is correct
12 Correct 70 ms 39516 KB Output is correct
13 Correct 67 ms 39228 KB Output is correct
14 Correct 70 ms 38732 KB Output is correct
15 Correct 86 ms 39712 KB Output is correct
16 Correct 73 ms 40388 KB Output is correct
17 Correct 72 ms 40572 KB Output is correct
18 Correct 67 ms 40888 KB Output is correct
19 Correct 71 ms 44996 KB Output is correct
20 Correct 72 ms 44828 KB Output is correct
21 Correct 70 ms 44564 KB Output is correct
22 Correct 14 ms 24012 KB Output is correct
23 Correct 13 ms 24036 KB Output is correct
24 Correct 15 ms 23980 KB Output is correct
25 Correct 14 ms 24164 KB Output is correct
26 Correct 13 ms 23808 KB Output is correct

Subtask #2
36.0 / 36.0

# 결과 실행 시간 메모리 Grader output
1 Correct 13 ms 23904 KB Output is correct
2 Correct 14 ms 24012 KB Output is correct
3 Correct 14 ms 24012 KB Output is correct
4 Correct 13 ms 24012 KB Output is correct
5 Correct 179 ms 66112 KB Output is correct
6 Correct 144 ms 66016 KB Output is correct
7 Correct 239 ms 65904 KB Output is correct
8 Correct 178 ms 66136 KB Output is correct
9 Correct 171 ms 65924 KB Output is correct
10 Correct 115 ms 66084 KB Output is correct
11 Correct 110 ms 66008 KB Output is correct
12 Correct 112 ms 65988 KB Output is correct
13 Correct 111 ms 66032 KB Output is correct
14 Correct 110 ms 66036 KB Output is correct
15 Correct 167 ms 66056 KB Output is correct
16 Correct 195 ms 66068 KB Output is correct
17 Correct 163 ms 66052 KB Output is correct
18 Correct 110 ms 66220 KB Output is correct
19 Correct 116 ms 66264 KB Output is correct
20 Correct 109 ms 66144 KB Output is correct
21 Correct 113 ms 66260 KB Output is correct
22 Correct 110 ms 66536 KB Output is correct
23 Correct 119 ms 66480 KB Output is correct
24 Correct 118 ms 66568 KB Output is correct
25 Correct 881 ms 106196 KB Output is correct

Subtask #3
41.0 / 41.0

# 결과 실행 시간 메모리 Grader output
1 Correct 13 ms 24012 KB Output is correct
2 Correct 13 ms 23956 KB Output is correct
3 Correct 69 ms 37496 KB Output is correct
4 Correct 73 ms 37564 KB Output is correct
5 Correct 76 ms 37552 KB Output is correct
6 Correct 91 ms 37620 KB Output is correct
7 Correct 73 ms 37652 KB Output is correct
8 Correct 72 ms 37688 KB Output is correct
9 Correct 73 ms 37804 KB Output is correct
10 Correct 72 ms 37604 KB Output is correct
11 Correct 87 ms 37680 KB Output is correct
12 Correct 70 ms 39516 KB Output is correct
13 Correct 67 ms 39228 KB Output is correct
14 Correct 70 ms 38732 KB Output is correct
15 Correct 86 ms 39712 KB Output is correct
16 Correct 73 ms 40388 KB Output is correct
17 Correct 72 ms 40572 KB Output is correct
18 Correct 67 ms 40888 KB Output is correct
19 Correct 71 ms 44996 KB Output is correct
20 Correct 72 ms 44828 KB Output is correct
21 Correct 70 ms 44564 KB Output is correct
22 Correct 14 ms 24012 KB Output is correct
23 Correct 13 ms 24036 KB Output is correct
24 Correct 15 ms 23980 KB Output is correct
25 Correct 14 ms 24164 KB Output is correct
26 Correct 13 ms 23808 KB Output is correct
27 Correct 13 ms 23904 KB Output is correct
28 Correct 14 ms 24012 KB Output is correct
29 Correct 14 ms 24012 KB Output is correct
30 Correct 13 ms 24012 KB Output is correct
31 Correct 179 ms 66112 KB Output is correct
32 Correct 144 ms 66016 KB Output is correct
33 Correct 239 ms 65904 KB Output is correct
34 Correct 178 ms 66136 KB Output is correct
35 Correct 171 ms 65924 KB Output is correct
36 Correct 115 ms 66084 KB Output is correct
37 Correct 110 ms 66008 KB Output is correct
38 Correct 112 ms 65988 KB Output is correct
39 Correct 111 ms 66032 KB Output is correct
40 Correct 110 ms 66036 KB Output is correct
41 Correct 167 ms 66056 KB Output is correct
42 Correct 195 ms 66068 KB Output is correct
43 Correct 163 ms 66052 KB Output is correct
44 Correct 110 ms 66220 KB Output is correct
45 Correct 116 ms 66264 KB Output is correct
46 Correct 109 ms 66144 KB Output is correct
47 Correct 113 ms 66260 KB Output is correct
48 Correct 110 ms 66536 KB Output is correct
49 Correct 119 ms 66480 KB Output is correct
50 Correct 118 ms 66568 KB Output is correct
51 Correct 881 ms 106196 KB Output is correct
52 Correct 1211 ms 163740 KB Output is correct
53 Correct 1187 ms 163920 KB Output is correct
54 Correct 1163 ms 161496 KB Output is correct
55 Correct 1159 ms 160964 KB Output is correct
56 Correct 1184 ms 162020 KB Output is correct
57 Correct 1223 ms 163604 KB Output is correct
58 Correct 14 ms 24012 KB Output is correct
59 Correct 15 ms 24036 KB Output is correct
60 Correct 14 ms 23964 KB Output is correct
61 Correct 1205 ms 163784 KB Output is correct
62 Correct 1218 ms 171016 KB Output is correct
63 Correct 1202 ms 166060 KB Output is correct
64 Correct 90 ms 39520 KB Output is correct
65 Correct 87 ms 39976 KB Output is correct
66 Correct 1223 ms 163864 KB Output is correct
67 Correct 1190 ms 163628 KB Output is correct
68 Correct 1057 ms 200192 KB Output is correct
69 Correct 1026 ms 200644 KB Output is correct
70 Correct 1085 ms 199828 KB Output is correct
71 Correct 1126 ms 199752 KB Output is correct
72 Correct 1082 ms 199948 KB Output is correct
73 Correct 975 ms 201412 KB Output is correct
74 Correct 1002 ms 202180 KB Output is correct
75 Correct 1040 ms 202012 KB Output is correct
76 Correct 1063 ms 202888 KB Output is correct
77 Correct 1014 ms 201636 KB Output is correct
78 Correct 992 ms 209636 KB Output is correct
79 Correct 1006 ms 209124 KB Output is correct
80 Correct 981 ms 207764 KB Output is correct
81 Correct 945 ms 224068 KB Output is correct
82 Correct 952 ms 225544 KB Output is correct
83 Correct 991 ms 225588 KB Output is correct
84 Correct 971 ms 236772 KB Output is correct
85 Correct 1006 ms 274572 KB Output is correct
86 Correct 996 ms 273428 KB Output is correct
87 Correct 997 ms 273488 KB Output is correct