Submission #877985

#	Time	Username	Problem	Language	Result	Execution time	Memory
877985		Regulus	Jail (JOI22_jail)	C++17	0 / 100	10 ms	17500 KiB

jail

#include <bits/stdc++.h>            // pA
#define IO ios::sync_with_stdio(false);cin.tie(0);
#define debug(x) cerr << #x << " = " << (x) << ' '
#define endl cerr << '\n'
#define all(v) (v).begin(), (v).end()
#define SZ(v) (ll)(v).size()
#define lowbit(x) (x)&-(x)
#define pb emplace_back
#define F first
#define S second
using namespace std;
using ll = long long;
using pll = pair<ll, ll>;
 
const int N = 2e5+5;
//const int INF = 2e9;
int s[N], t[N], state[N], tin[N], sz[N], timer, tout[N];
vector<int> g[N];
 
inline void dfs(int x, int pre)
{
    tin[x] = ++timer, sz[x] = 1;
    for (int v : g[x])
    {
        if (v == pre) continue;
        state[v] |= state[x];
        dfs(v, x);
        sz[x] += sz[v];
    }
    tout[x] = ++timer;
}
 
inline bool is_anc(int x, int y)
{
    return tin[x] <= tin[y] && tout[y] <= tout[x];
}
 
int main(void)
{ IO
    ll T, n, i, m, x, y;
 
    cin >> T;
    do {
        cin >> n;
        for (i=1; i <= n; ++i) tin[i] = tout[i] = sz[i] = state[i] = 0, g[i].clear();
        for (i=0; i < n-1; ++i) cin >> x >> y, g[x].pb(y), g[y].pb(x);
        
        cin >> m;
        if (m > 2) assert(0);
        for (i=1; i <= m; ++i) cin >> s[i] >> t[i];
 
        state[s[2]] |= 1, state[t[2]] |= 2;
        timer = 0;
        dfs(s[1], 0);
 
        if ((state[t[1]]&3) == 3)
        {
            cout << "No\n";
        } else if (state[t[1]]&2) {
            if (is_anc(t[1], s[2])) cout << "No\n";
            else cout << "Yes\n";
        } else if (state[t[1]]&1) {
            if (!is_anc(t[1], t[2])) cout << "No\n";
            else cout << "Yes\n";
        } else {        // debug..
            if (is_anc(t[1], t[2]) || is_anc(t[1], s[2])) cout << "No\n";
            else cout << "Yes\n";
        }
    } while (--T);
 
    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