Submission #1089876

#	Time	Username	Problem	Language	Result	Execution time	Memory
1089876		Neco_arc	Jail (JOI22_jail)	C++17	100 / 100	878 ms	317972 KiB

jail

#include <bits/stdc++.h>
#ifdef LOCAL
#include <bits/debug.hpp>
#endif // LOCAL

#define ll long long
#define all(x) x.begin(), x.end()
#define Neco "Jail"
#define resp(x) sort(all(x)), x.resize(unique(all(x)) - x.begin())
#define getbit(x,i) ((x >> i)&1)
#define _left id * 2, l, mid
#define _right id * 2 + 1, mid + 1, r
#define cntbit(x) __builtin_popcountll(x)
#define fi(i, a, b) for(int i = a; i <= b; i++)
#define fid(i, a, b) for(int i = a; i >= b; i--)
#define maxn (int) 120009

using namespace std;

const ll mod = 1e9 + 7; //972663749
const ll base = 911382323;

int n, q, N;
int deg[40 * maxn], h[maxn];
int cha[maxn][18], Sx[maxn][18], Tx[maxn][18];
int Sv[maxn], Tv[maxn], S[maxn], T[maxn];
vector<int> edges[maxn], g[40 * maxn];

void pre_dfs(int u, int par) {
    for(int v : edges[u]) if(v != par) {
        h[v] = h[u] + 1, cha[v][0] = u;
        fi(i, 1, 17) cha[v][i] = cha[cha[v][i - 1]][i - 1];

        pre_dfs(v, u);
    }
}

int lca(int u, int v) {
    if(h[u] < h[v]) swap(u, v);
    fid(i, 17, 0) if(h[u] - (1 << i) >= h[v]) u = cha[u][i];
    fid(i, 17, 0) if(cha[u][i] != cha[v][i]) u = cha[u][i], v = cha[v][i];
    return u == v ? u : cha[u][0];
}

void AddS(int id, int x, int h) {
    fid(i, 17, 0) if(getbit(h, i)) {
        g[Sx[x][i]].push_back(id);
        x = cha[x][i];
    }
}

void AddT(int id, int x, int h) {
    fid(i, 17, 0) if(getbit(h, i)) {
        g[id].push_back(Tx[x][i]);
        x = cha[x][i];
    }
}

bool TopoSort() {
    queue<int> q;
    fi(u, 1, N) for(int v : g[u]) ++deg[v];
    fi(i, 1, N) {
        if(!deg[i]) q.push(i);
    }

    int cnt = 0;
    while(!q.empty()) {
        ++cnt;
        int u = q.front(); q.pop();
        for(int v : g[u]) {
            --deg[v];
            if(!deg[v]) q.push(v);
        }
    }

    return cnt == N;

}

void reset() {
    fi(i, 1, n) fi(j, 0, 17) cha[i][j] = 0;
    fi(i, 1, n) edges[i].clear(), Sv[i] = Tv[i] = 0;
    fi(i, 1, N) g[i].clear(), deg[i] = 0;
    N = 0;
}

void solve()
{

    cin >> n;
    fi(i, 1, n - 1) {
        int x, y; cin >> x >> y;
        edges[x].push_back(y), edges[y].push_back(x);
    }

    cin >> q;
    fi(i, 1, q) {
        cin >> S[i] >> T[i];
        Sv[S[i]] = i, Tv[T[i]] = i;
    }

    N = q;
    pre_dfs(1, 0);

    fi(j, 0, 17) fi(i, 1, n) {
        Tx[i][j] = ++N;
        Sx[i][j] = ++N;
    }

    fi(j, 0, 17) fi(i, 1, n) if(cha[i][j]) {
        int p = cha[i][j], ids = Sx[i][j + 1], idt = Tx[i][j + 1];
        g[Sx[i][j]].push_back(ids);
        g[idt].push_back(Tx[i][j]);

//        cout << Sx[i][j] << " " << ids << '\n';

        if(p) {
            g[Sx[p][j]].push_back(ids);
//            cout << Sx[p][j] << " " << ids << '\n';
            g[idt].push_back(Tx[p][j]);
        }
    }


    fi(i, 1, n) {
        int p = cha[i][0];
        if(Sv[p]) g[Sv[p]].push_back(Sx[i][0]);
        if(Tv[p]) g[Tx[i][0]].push_back(Tv[p]);
    }


    fi(i, 1, q) {
        int x = S[i], y = T[i], p = lca(x, y);
        if(x == y) continue;

        int Ls = h[x] - h[p], Lt = h[y] - h[p];

        if(Ls >= 2) {
            AddS(i, x, Ls - 1);
            AddT(i, x, Ls - 1);
        }

        if(Lt >= 2) {
            AddS(i, y, Lt - 1);
            AddT(i, y, Lt - 1);
        }

        int tv[] = {x, y, p};
        for(int u : tv) {
            if(Sv[u] && Sv[u] != i) g[Sv[u]].push_back(i);
            if(Tv[u] && Tv[u] != i) g[i].push_back(Tv[u]);
        }
    }

    if(TopoSort()) cout << "Yes\n";
    else cout << "No\n";

    reset();
}


int main()
{

    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    if(fopen(Neco".inp", "r")) {
        freopen(Neco".inp", "r", stdin);
        freopen(Neco".out", "w", stdout);
    }


    int nTest = 1;
    cin >> nTest;


    while(nTest--)
    {
        solve();
    }


    return 0;
}

Compilation message (stderr)

jail.cpp: In function 'int main()':
jail.cpp:170:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  170 |         freopen(Neco".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
jail.cpp:171:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  171 |         freopen(Neco".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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