Submission #712894

#	Time	Username	Problem	Language	Result	Execution time	Memory
712894		GrindMachine	Jail (JOI22_jail)	C++17	0 / 100	5073 ms	74588 KiB

jail

// Om Namah Shivaya

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x, y) ((x + y - 1) / (y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl

#define rep(i, n) for(int i = 0; i < n; ++i)
#define rep1(i, n) for(int i = 1; i <= n; ++i)
#define rev(i, s, e) for(int i = s; i >= e; --i)
#define trav(i, a) for(auto &i : a)

template<typename T>
void amin(T &a, T b) {
    a = min(a, b);
}

template<typename T>
void amax(T &a, T b) {
    a = max(a, b);
}

#ifdef LOCAL
#include "debug.h"
#else
#define debug(x) 42
#endif

/*



*/

const int MOD = 1e9 + 7;
const int N = 120000 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;

vector<pll> adj[N];
vector<pll> edges(N);
vector<ll> dir(N);
vector<array<ll, 3>> curr;
vector<ll> curr_nodes;
vector<ll> nodes;
bool reach;

void dfs(ll u, ll p, ll des) {
    curr_nodes.pb(u);

    if (u == des) {
        nodes = curr_nodes;

        reach = true;
        for (auto [x, y, id] : curr) {
            if (x == edges[id].ff and y == edges[id].ss) {
                dir[id] = 0;
            }
            else {
                dir[id] = 1;
            }
        }
    }

    for (auto [v, id] : adj[u]) {
        if (v == p) conts;

        bool good = false;

        if (dir[id] == -1) {
            good = true;
        }
        else if (dir[id] == 0) {
            if (u == edges[id].ff and v == edges[id].ss) {
                good = true;
            }
        }
        else {
            if (u == edges[id].ss and v == edges[id].ff) {
                good = true;
            }
        }

        if (good) {
            curr.pb({u, v, id});
            dfs(v, u, des);
            curr.pop_back();
        }
    }

    curr_nodes.pop_back();
}

void solve(int test_case)
{
    ll n; cin >> n;

    rep1(i, n) {
        adj[i].clear();
        dir[i] = -1;
    }

    rep1(i, n - 1) {
        ll u, v; cin >> u >> v;
        edges[i] = {u, v};
        adj[u].pb({v, i}), adj[v].pb({u, i});
    }

    ll m; cin >> m;
    vector<pll> came;

    while (m--) {
        assert(curr.empty());
        assert(curr_nodes.empty());

        ll u, v; cin >> u >> v;
        reach = false;
        dfs(u, -1, v);

        if (!reach) {
            no;
            return;
        }

        sort(all(nodes));

        for (auto [x, y] : came) {
            if (binary_search(all(nodes), x)) {
                if (binary_search(all(nodes), y)) {
                    no;
                    return;
                }
            }
        }

        came.pb({u, v});
    }

    yes;
}

int main()
{
    fastio;

    int t = 1;
    cin >> t;

    rep1(i, t) {
        solve(i);
    }

    return 0;
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 5
• Subtask 3: 0 / 16
• Subtask 4: 0 / 28
• Subtask 5: 0 / 12
• Subtask 6: 0 / 11
• Subtask 7: 0 / 23