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답안 #773683

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
773683 2023-07-05T07:46:33 Z ParsaS LOSTIKS (INOI20_lostiks) C++17
59 / 100
 2000 ms 604064 KB 
// In the name of God
//#pragma GCC optimize("O2", "unroll-loops")
#include<bits/stdc++.h>
using namespace std;
#define pb push_back
#define fi first
#define se second
#define mp make_pair
typedef long long ll;
const int N = 1e6 + 5, lg = 21;
int n, c, s, t;
vector<int> adj[N];
vector<pair<int, int> > E;
int f[N], tin[N], tout[N], T, h[N], up[N][lg];
int dis[lg][N];
ll dp[1 << lg][lg];
bool ok[1 << lg][lg];

void dfs(int v, int p) {
    tin[v] = ++T;
    up[v][0] = p;
    for (int i = 1; i < lg; i++) {
        up[v][i] = up[up[v][i - 1]][i - 1];
    }
    for (auto u : adj[v]) {
        if (u != p) {
            h[u] = h[v] + 1;
            dfs(u, v);
        }
    }
    tout[v] = ++T;
}
void dfs2(int v, int p, int k) {
    for (auto u : adj[v]) {
        if (u != p) {
            dis[k][u] = dis[k][v] + 1;
            dfs2(u, v, k);
        }
    }
}
bool anc(int v, int u) {
    return tin[v] <= tin[u] && tout[v] >= tout[u];
}
int lca(int v, int u) {
    if (tin[v] > tin[u])
        swap(v, u);
    if (anc(v, u))
        return v;
    for (int i = lg - 1; i >= 0; i--)
        if (!anc(up[u][i], v))
            u = up[u][i];
    return up[u][0];
}
void solve() {
	set<int> st;
    cin >> n >> s >> t;
    for (int i = 0; i < n - 1; i++) {
        int v, u, w; cin >> v >> u >> w;
        adj[v].pb(u), adj[u].pb(v);
        if (w) {
            f[(int)E.size()] = w, E.pb(mp(v, u));
            st.insert(w);
        }
    }
	st.insert(t);
    dfs(s, 0);
    tout[0] = ++T;

    c = (int)E.size();
    assert(c <= 20);
    memset(dis, 63, sizeof dis);

    for (int i = 0; i < c; i++) {
        if (tin[E[i].fi] > tin[E[i].se])
            swap(E[i].fi, E[i].se);
        //dfs2(E[i].fi, 0, i);
        for (auto v : st) {
            //assert(dis[i][v] == h[E[i].fi] + h[v] - 2 * h[lca(E[i].fi, v)]);
            dis[i][v] = h[E[i].fi] + h[v] - 2 * h[lca(E[i].fi, v)];
        }
    }
    E.pb(mp(t, t));
    f[c] = t;
    for (int mask = 0; mask < (1 << c); mask++) {
        for (int i = 0; i <= c; i++) {
            int v = E[i].fi;
            ok[mask][i] = true;
            for (int j = 0; j < c; j++) {
                ok[mask][i] &= (mask & (1 << j)) || (!anc(E[j].se, v) && !anc(E[j].se, f[i]));
            }
        }
    }
    memset(dp, 63, sizeof dp);
    for (int i = 0; i < c; i++) {
        if (ok[1 << i][i]) {
            dp[1 << i][i] = h[f[i]] + dis[i][f[i]];
        }
    }
    ll ans = 1e18;
    if (ok[0][c]) {
        ans = h[t];
    }
    for (int mask = 1; mask < (1 << c); mask++) {
        for (int i = 0; i < c; i++) {
            if (!(mask & (1 << i)))
                continue;

            int mask2 = mask ^ (1 << i);
            for (int j = 0; j < c; j++) {
                if (mask2 & (1 << j)) {
                    if (ok[mask2][i]) {
                        dp[mask][i] = min(dp[mask][i], dp[mask2][j] + dis[j][f[i]] + dis[i][f[i]]);
                    }
                }
            }

            if (ok[mask][c]) {
                ans = min(ans, dp[mask][i] + dis[i][t]);
            }
        }
    }

    if (ans < 1e18)
        cout << ans << '\n';
    else
        cout << -1 << '\n';
}

int32_t main() {
    ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
    solve();
    return 0;
}

Subtask #1
23.0 / 23.0

# 결과 실행 시간 메모리 Grader output
1 Correct 145 ms 450680 KB Output is correct
2 Correct 142 ms 450636 KB Output is correct
3 Correct 191 ms 463612 KB Output is correct
4 Correct 189 ms 464840 KB Output is correct
5 Correct 192 ms 464776 KB Output is correct
6 Correct 205 ms 464776 KB Output is correct
7 Correct 195 ms 464960 KB Output is correct
8 Correct 202 ms 464928 KB Output is correct
9 Correct 203 ms 465064 KB Output is correct
10 Correct 198 ms 464924 KB Output is correct
11 Correct 194 ms 465016 KB Output is correct
12 Correct 203 ms 466400 KB Output is correct
13 Correct 192 ms 466080 KB Output is correct
14 Correct 195 ms 465732 KB Output is correct
15 Correct 199 ms 466568 KB Output is correct
16 Correct 196 ms 467072 KB Output is correct
17 Correct 202 ms 467080 KB Output is correct
18 Correct 193 ms 467552 KB Output is correct
19 Correct 207 ms 470684 KB Output is correct
20 Correct 209 ms 470596 KB Output is correct
21 Correct 215 ms 470404 KB Output is correct
22 Correct 141 ms 450684 KB Output is correct
23 Correct 140 ms 450688 KB Output is correct
24 Correct 156 ms 450748 KB Output is correct
25 Correct 142 ms 450764 KB Output is correct
26 Correct 144 ms 450728 KB Output is correct

Subtask #2
36.0 / 36.0

# 결과 실행 시간 메모리 Grader output
1 Correct 142 ms 450656 KB Output is correct
2 Correct 144 ms 450652 KB Output is correct
3 Correct 143 ms 450708 KB Output is correct
4 Correct 141 ms 450852 KB Output is correct
5 Correct 1380 ms 462528 KB Output is correct
6 Correct 1366 ms 462520 KB Output is correct
7 Correct 1330 ms 462508 KB Output is correct
8 Correct 1348 ms 462512 KB Output is correct
9 Correct 1357 ms 462436 KB Output is correct
10 Correct 1219 ms 462440 KB Output is correct
11 Correct 1197 ms 462524 KB Output is correct
12 Correct 1218 ms 462520 KB Output is correct
13 Correct 1181 ms 462540 KB Output is correct
14 Correct 1155 ms 462440 KB Output is correct
15 Correct 1296 ms 462540 KB Output is correct
16 Correct 1308 ms 462548 KB Output is correct
17 Correct 1303 ms 462556 KB Output is correct
18 Correct 1179 ms 462660 KB Output is correct
19 Correct 1138 ms 462776 KB Output is correct
20 Correct 1172 ms 462748 KB Output is correct
21 Correct 1144 ms 462660 KB Output is correct
22 Correct 1104 ms 462948 KB Output is correct
23 Correct 1110 ms 462912 KB Output is correct
24 Correct 1114 ms 462836 KB Output is correct
25 Correct 1862 ms 472276 KB Output is correct

Subtask #3
0 / 41.0

# 결과 실행 시간 메모리 Grader output
1 Correct 145 ms 450680 KB Output is correct
2 Correct 142 ms 450636 KB Output is correct
3 Correct 191 ms 463612 KB Output is correct
4 Correct 189 ms 464840 KB Output is correct
5 Correct 192 ms 464776 KB Output is correct
6 Correct 205 ms 464776 KB Output is correct
7 Correct 195 ms 464960 KB Output is correct
8 Correct 202 ms 464928 KB Output is correct
9 Correct 203 ms 465064 KB Output is correct
10 Correct 198 ms 464924 KB Output is correct
11 Correct 194 ms 465016 KB Output is correct
12 Correct 203 ms 466400 KB Output is correct
13 Correct 192 ms 466080 KB Output is correct
14 Correct 195 ms 465732 KB Output is correct
15 Correct 199 ms 466568 KB Output is correct
16 Correct 196 ms 467072 KB Output is correct
17 Correct 202 ms 467080 KB Output is correct
18 Correct 193 ms 467552 KB Output is correct
19 Correct 207 ms 470684 KB Output is correct
20 Correct 209 ms 470596 KB Output is correct
21 Correct 215 ms 470404 KB Output is correct
22 Correct 141 ms 450684 KB Output is correct
23 Correct 140 ms 450688 KB Output is correct
24 Correct 156 ms 450748 KB Output is correct
25 Correct 142 ms 450764 KB Output is correct
26 Correct 144 ms 450728 KB Output is correct
27 Correct 142 ms 450656 KB Output is correct
28 Correct 144 ms 450652 KB Output is correct
29 Correct 143 ms 450708 KB Output is correct
30 Correct 141 ms 450852 KB Output is correct
31 Correct 1380 ms 462528 KB Output is correct
32 Correct 1366 ms 462520 KB Output is correct
33 Correct 1330 ms 462508 KB Output is correct
34 Correct 1348 ms 462512 KB Output is correct
35 Correct 1357 ms 462436 KB Output is correct
36 Correct 1219 ms 462440 KB Output is correct
37 Correct 1197 ms 462524 KB Output is correct
38 Correct 1218 ms 462520 KB Output is correct
39 Correct 1181 ms 462540 KB Output is correct
40 Correct 1155 ms 462440 KB Output is correct
41 Correct 1296 ms 462540 KB Output is correct
42 Correct 1308 ms 462548 KB Output is correct
43 Correct 1303 ms 462556 KB Output is correct
44 Correct 1179 ms 462660 KB Output is correct
45 Correct 1138 ms 462776 KB Output is correct
46 Correct 1172 ms 462748 KB Output is correct
47 Correct 1144 ms 462660 KB Output is correct
48 Correct 1104 ms 462948 KB Output is correct
49 Correct 1110 ms 462912 KB Output is correct
50 Correct 1114 ms 462836 KB Output is correct
51 Correct 1862 ms 472276 KB Output is correct
52 Correct 1480 ms 585548 KB Output is correct
53 Correct 1408 ms 585596 KB Output is correct
54 Correct 1289 ms 588216 KB Output is correct
55 Correct 1245 ms 587920 KB Output is correct
56 Correct 1281 ms 588772 KB Output is correct
57 Correct 1257 ms 589992 KB Output is correct
58 Correct 148 ms 450708 KB Output is correct
59 Correct 147 ms 450676 KB Output is correct
60 Correct 143 ms 450692 KB Output is correct
61 Correct 1243 ms 590296 KB Output is correct
62 Correct 1478 ms 590444 KB Output is correct
63 Correct 1307 ms 596044 KB Output is correct
64 Correct 197 ms 466396 KB Output is correct
65 Correct 199 ms 466636 KB Output is correct
66 Correct 1234 ms 597268 KB Output is correct
67 Correct 1290 ms 596880 KB Output is correct
68 Execution timed out 2105 ms 604064 KB Time limit exceeded
69 Halted 0 ms 0 KB -