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IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#692375#5439. Meet in the MiddleNATORE 0ms0kbC++233.0kb2024-10-31 14:24:372024-10-31 14:24:38

Judging History

你现在查看的是最新测评结果

  • [2024-10-31 14:24:38]
  • 评测
  • 测评结果:RE
  • 用时:0ms
  • 内存:0kb
  • [2024-10-31 14:24:37]
  • 提交

answer

#include <bits/stdc++.h>
#define ll long long

#define INF 214748364719260817ll

#define MAXN 2147483647ll

using namespace std;
ll n, m;
struct graph {
    ll head[100005], cnt;
    struct ed {
        ll v, next, w;
    } edge[200005];
    void add(ll u, ll v, ll w) {
        edge[++cnt].v = v;
        edge[cnt].next = head[u];
        head[u] = cnt;
        edge[cnt].w = w;
        edge[++cnt].v = u;
        edge[cnt].next = head[v];
        head[v] = cnt;
        edge[cnt].w = w;
    }
    int f[200005][20];
    ll tot, lg[200005], dfn[200005], dep[200005], dis[200005];
    int from[200005][20];
    void clear() {
        for (ll i = 1; i <= n; ++i) head[i] = 0;
        cnt = tot = 0;
    }
    void dfs(ll id, ll fa) {
        dep[id] = dep[fa] + 1;
        f[dfn[id] = ++tot][0] = f[dfn[fa]][0] + 1;
        from[dfn[id]][0] = id;
        for (ll i = head[id]; i; i = edge[i].next) {
            ll v = edge[i].v, w = edge[i].w;
            if (v == fa)
                continue;
            dis[v] = dis[id] + w;
            dfs(v, id);
            f[++tot][0] = dep[id];
            from[tot][0] = id;
        }
    }
    ll get_lca(ll u, ll v) {
        if (dfn[u] > dfn[v])
            swap(u, v);
        ll use = lg[dfn[v] - dfn[u] + 1];
        ll r1 = from[dfn[u]][use], r2 = from[dfn[v] - (1 << use) + 1][use];
        return dep[r1] < dep[r2] ? r1 : r2;
    }
    void init() {
        ll u, v, w;
        for (ll i = 1; i < n; ++i) cin >> u >> v >> w, add(u, v, w);
        for (ll i = 2; i <= 2 * n - 1; ++i) lg[i] = lg[i >> 1] + 1;
        dfs(1, 0);
        for (ll i = tot; i > 0; --i)
            for (ll j = 1; (i + (1 << j) - 1) <= tot; ++j) {
                f[i][j] = f[i][j - 1];
                from[i][j] = from[i][j - 1];
                if (f[i][j] > f[i + (1 << (j - 1))][j - 1])
                    f[i][j] = f[i + (1 << (j - 1))][j - 1], from[i][j] = from[i + (1 << (j - 1))][j - 1];
            }
    }
    ll get_dis(ll u, ll v) { return dis[u] + dis[v] - 2 * dis[get_lca(u, v)]; }
} g[2];

ll t;
int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    cin >> t;
    random_device my;
    mt19937 rd(my());
    while (t--) {
        g[0].clear();
        g[1].clear();
        cin >> n;
        g[0].init();
        g[1].init();
        set<ll> p;
        for (ll i = 1; i <= 200; ++i) {
            ll u = rd() % n + 1, v = rd() % n + 1;
            ll maxn = -1, uid = 0;
            for (ll j = 1; j <= n; ++j) {
                ll val = g[0].get_dis(u, j) + g[1].get_dis(v, j);
                if (val > maxn)
                    maxn = val, uid = j;
            }
            p.insert(uid);
        }
        cin >> m;
        while (m--) {
            ll u, v;
            cin >> u >> v;
            ll maxn = -1;
            for (auto it : p) {
                ll val = g[0].get_dis(u, it) + g[1].get_dis(v, it);
                maxn = max(maxn, val);
            }
            cout << maxn << '\n';
        }
    }
}

Details

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Test #1:

score: 0
Runtime Error

input:

3 4
1 2 1
2 3 2
1 2 2
2 3 1
1 1
1 2
2 1
2 2

output:


result: