Submission #598140

#	Time	Username	Problem	Language	Result	Execution time	Memory
598140		dxz05	Jail (JOI22_jail)	C++14	0 / 100	15 ms	9760 KiB

jail

//#pragma GCC optimize("Ofast,O2,O3,unroll-loops")
//#pragma GCC target("avx2")

#include <bits/stdc++.h>

using namespace std;

void debug_out() { cerr << endl; }

template<typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
    cerr << "[" << H << "]";
    debug_out(T...);
}

#ifdef dddxxz
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#else
#define debug(...) 42
#endif

#define SZ(s) ((int)s.size())
#define all(x) (x).begin(), (x).end()
#define lla(x) (x).rbegin(), (x).rend()
#define bpc(x) __builtin_popcount(x)
#define bpcll(x) __builtin_popcountll(x)
#define MP make_pair

clock_t startTime;

double getCurrentTime() {
    return (double) (clock() - startTime) / CLOCKS_PER_SEC;
}

mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());

typedef long long ll;
const int MOD = 1e9 + 7;
const int INF = 1000000101;
const long long LLINF = 1223372000000000555;
const int N = 2e5 + 3e2;
const int M = 5555;

vector<int> g[N];

int tin[N], tout[N], timer = 0;
int up[N][18], depth[N];

inline void dfs(int v, int p){
    tin[v] = ++timer;
    depth[v] = depth[p] + 1;

    up[v][0] = p;
    for (int i = 1; i < 18; i++){
        up[v][i] = up[up[v][i - 1]][i - 1];
    }
    for (int u : g[v]){
        if (u != p) dfs(u, v);
    }
    tout[v] = ++timer;
}

inline bool upper(int u, int v){
    return tin[u] <= tin[v] && tout[v] <= tout[u];
}

inline int lca(int u, int v){
    if (upper(u, v)) return u;
    if (upper(v, u)) return v;
    for (int i = 17; i >= 0; i--){
        if (!upper(up[u][i], v)) u = up[u][i];
    }
    return up[u][0];
}

inline int dist(int u, int v){
    return depth[u] + depth[v] - 2 * depth[lca(u, v)];
}

inline bool in(int a, int b, int c){
    return dist(a, c) == dist(a, b) + dist(b, c);
}

vector<int> gg[N];
inline bool jail(int n, int m, vector<int> S, vector<int> T){
    for (int i = 0; i < m; i++){
        for (int j = i + 1; j < m; j++){
            if (in(S[i], S[j], T[i]) && in(S[i], T[j], T[i])) return false;
            if (in(S[j], S[i], T[j]) && in(S[j], T[i], T[j])) return false;

            int x = -1, y = -1;
            if (in(S[j], S[i], T[j])) x = S[i];
            if (in(S[j], T[i], T[j])) x = T[i];
            if (in(S[i], S[j], T[i])) y = S[j];
            if (in(S[i], T[j], T[i])) y = T[j];

            if (x == -1 && y == -1) continue;
            bool ok = false;

            if (x == -1){
                gg[i].push_back(j);
                ok = true;
            }
            if (y == -1){
                gg[j].push_back(i);
                ok = true;
            }

            if (x == y){
                if (x == S[i]) gg[i].push_back(j); else
                    gg[j].push_back(i);
                ok = true;
            }

            if (x == S[i] && y == T[j]){
                gg[i].push_back(j);
                ok = true;
            }
            if (x == T[i] && y == S[j]){
                gg[j].push_back(i);
                ok = true;
            }

//            if (!ok) return false;
        }
    }

    return true;
}

int color[N];
bool dfs(int v){
    color[v] = 1;
    for (int u : gg[v]){
        if (color[u] == 1) return true;
        if (color[u] == 0 && dfs(u)) return true;
    }
    color[v] = 2;
    return false;
}

void solve(int TC) {
    int n;
    cin >> n;

    timer = 0;
    for (int i = 0; i < n; i++) g[i].clear();

    for (int i = 0; i < n - 1; i++){
        int a, b;
        cin >> a >> b;
        --a, --b;
        g[a].push_back(b);
        g[b].push_back(a);
    }

    dfs(0, 0);

    int m;
    cin >> m;

    vector<int> S(m), T(m);
    for (int i = 0; i < m; i++){
        cin >> S[i] >> T[i];
        S[i]--, T[i]--;
    }

    for (int i = 0; i < m; i++){
        gg[i].clear();
        color[i] = 0;
    }

    if (!jail(n, m, S, T)){
        cout << "No\n";
        return;
    }

    for (int i = 0; i < m; i++){
        if (color[i] == 0 && dfs(i)){
            cout << "No\n";
            return;
        }
    }

    cout << "Yes\n";

}

int main() {
    startTime = clock();
    ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);

#ifdef dddxxz
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif

    int TC = 1;
    cin >> TC;

    for (int test = 1; test <= TC; test++) {
        //debug(test);
        //cout << "Case #" << test << ": ";
        solve(test);
    }

#ifdef dddxxz
    cerr << endl << "Time: " << int(getCurrentTime() * 1000) << " ms" << endl;
#endif

    return 0;
}

Compilation message (stderr)

jail.cpp: In function 'bool jail(int, int, std::vector<int>, std::vector<int>)':
jail.cpp:98:18: warning: variable 'ok' set but not used [-Wunused-but-set-variable]
   98 |             bool ok = false;
      |                  ^~

• 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