oj.uz

Submission #948159

# Submission time Handle Problem Language Result Execution time Memory
948159 2024-03-17T17:04:10 Z Nhoksocqt1 Thousands Islands (IOI22_islands) C++17
39.4 / 100
 194 ms 19796 KB 
#ifndef Nhoksocqt1
    #include "islands.h"
#endif // Nhoksocqt1
#include<bits/stdc++.h>
using namespace std;

#define inf 0x3f3f3f3f
#define sz(x) int((x).size())
#define fi first
#define se second
typedef long long ll;
typedef pair<int, int> ii;

template<class X, class Y>
	inline bool maximize(X &x, const Y &y) {return (x < y ? x = y, 1 : 0);}
template<class X, class Y>
	inline bool minimize(X &x, const Y &y) {return (x > y ? x = y, 1 : 0);}

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int Random(int l, int r) {
    return uniform_int_distribution<int>(l, r)(rng);
}

const int MAXN = 100005;

vector<ii> adj[MAXN];
map<ii, int> cntEdge;
ii edge[2 * MAXN];
int low[MAXN], num[MAXN], tr[MAXN], numNode, numEdge;
bool dx[MAXN], dxt[2 * MAXN];

int getCntEdge(ii p) {
    return (cntEdge.find(p) != cntEdge.end()) ? cntEdge[p] : 0;
}

void dfs(int u, int lastID = -1) {
    dx[u] = 1;
    tr[u] = lastID;
    for (int it = 0; it < sz(adj[u]); ++it) {
        int v(adj[u][it].fi), id(adj[u][it].se);
        if(!dx[v])
            dfs(v, id);
    }
}

stack<int> st;
bool tarjan(int u) {
    st.push(u);
    low[u] = num[u] = ++num[numNode];

    for (int it = 0; it < sz(adj[u]); ++it) {
        int v(adj[u][it].fi), id(adj[u][it].se);
        if(!dxt[id]) {
            dxt[id] = 1;
            if(!num[v]) {
                if(tarjan(v))
                    return true;

                low[u] = min(low[u], low[v]);
            } else {
                low[u] = min(low[u], num[v]);
            }
        }
    }

    if(low[u] == num[u]) {
        int v, cnt(0);
        do {
            v = st.top(); st.pop();
            low[v] = num[v] = 1e9+7;
            ++cnt;
        } while(v != u);
        return (cnt > 2);
    }

    return false;
}

#ifdef Nhoksocqt1
    vector<int>
#else
    variant<bool, vector<int>>
#endif // Nhoksocqt1
    find_journey(int _N, int _M, vector<int> _U, vector<int> _V) {
    numNode = _N, numEdge = _M;
    for (int i = 0; i < numEdge; ++i) {
        int u(_U[i]), v(_V[i]);
        edge[i] = {u, v};
        ++cntEdge[ii(u, v)];
        adj[u].push_back(ii(v, i));
    }

    dfs(0);
    int x(-1), y(-1), z(-1);
    for (int i = 0; i < numNode; ++i) {
        if(dx[i]) {
            int t1(-1);
            for (int it = 0; it < sz(adj[i]); ++it) {
                int j(adj[i][it].fi);

                if(edge[tr[i]].fi != j && getCntEdge(ii(j, i)) > 0) {
                    if(t1 < 0) {
                        t1 = j;
                    } else
                        if(t1 != j) {
                            x = i, y = t1, z = j;
                            break;
                        }
                }
            }

            if(y >= 0)
                break;
        }
    }

    if(z >= 0) {
        int idx_y(-1), idy_x(-1), idx_z(-1), idz_x(-1);
        for (int i = 0; i < numEdge; ++i) {
            int u(edge[i].fi), v(edge[i].se);
            if(u == x && v == y)
                idx_y = i;

            if(u == y && v == x)
                idy_x = i;

            if(u == x && v == z)
                idx_z = i;

            if(u == z && v == x)
                idz_x = i;
        }

        vector<int> ans, pf;
        int u(x);
        while(u != 0) {
            ans.push_back(tr[u]);
            u = edge[tr[u]].fi;
        }

        pf = ans;
        reverse(ans.begin(), ans.end());

        vector<int> p({idx_y, idy_x, idx_z, idz_x, idy_x, idx_y, idz_x, idx_z});
        for (int it = 0; it < sz(p); ++it)
            ans.push_back(p[it]);

        for (int it = 0; it < sz(pf); ++it)
            ans.push_back(pf[it]);

        return ans;
    }

    for (int i = 0; i < numNode; ++i) {
        if(!dx[i])
            continue;

        for (int it = 0; it < sz(adj[i]); ++it) {
            int j(adj[i][it].fi);
            if(edge[tr[i]].fi != j && getCntEdge(ii(i, j)) > 1 && getCntEdge(ii(j, i)) > 0) {
                x = i, y = j;
                break;
            }
        }

        if(y >= 0)
            break;
    }

    if(y >= 0) {
        int idx_y_1(-1), idy_x(-1), idx_y_2(-1);
        for (int i = 0; i < numEdge; ++i) {
            int u(edge[i].fi), v(edge[i].se);
            if(u == x && v == y) {
                if(idx_y_1 < 0) {
                    idx_y_1 = i;
                } else {
                    idx_y_2 = i;
                }
            }

            if(u == y && v == x)
                idy_x = i;
        }

        vector<int> ans, pf;
        int u(x);
        while(u != 0) {
            ans.push_back(tr[u]);
            u = edge[tr[u]].fi;
        }

        pf = ans;
        reverse(ans.begin(), ans.end());

        vector<int> p({idx_y_1, idy_x, idx_y_2, idx_y_1, idy_x, idx_y_2});
        for (int it = 0; it < sz(p); ++it)
            ans.push_back(p[it]);

        for (int it = 0; it < sz(pf); ++it)
            ans.push_back(pf[it]);

        return ans;
    }

    for (int i = 0; i <= numNode; ++i) {
        low[i] = num[i] = 0;
        adj[i].clear();
    }

    for (int i = 0; i < numEdge; ++i) {
        int u(edge[i].fi), v(edge[i].se);
        if(getCntEdge(ii(u, v)) > 1)
            adj[u].push_back(ii(v, i));
    }

    if(tarjan(0))
        return true;

    #ifdef Nhoksocqt1
        return {-1};
    #else
        return false;
    #endif // Nhoksocqt1
}

#ifdef Nhoksocqt1

int main(void) {
    ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);

    #define TASK "islands"
    if(fopen(TASK".inp", "r")) {
        freopen(TASK".inp", "r", stdin);
        freopen(TASK".out", "w", stdout);
    }

    vector<int> _U, _V;
    int _N, _M;
    cin >> _N >> _M;

    _U.resize(_M), _V.resize(_M);
    for (int i = 0; i < _M; ++i)
        cin >> _U[i] >> _V[i];

    vector<int> p = find_journey(_N, _M, _U, _V);
    cout << "ANSWER: ";
    if(sz(p) == 1 && p[0] == -1) {
        cout << "NO\n";
    } else {
        for (int it = 0; it < sz(p); ++it)
            cout << p[it] << ' ';

        cout << '\n';
    }

    return 0;
}

#endif // Nhoksocqt1

Subtask #1
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 5468 KB Output is correct
2 Correct 1 ms 5468 KB Output is correct
3 Correct 2 ms 5468 KB Output is correct
4 Correct 1 ms 5468 KB Output is correct
5 Correct 1 ms 5468 KB Output is correct
6 Correct 1 ms 5468 KB Output is correct
7 Correct 37 ms 10460 KB Output is correct

Subtask #2
5.0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 5464 KB Output is correct
2 Correct 2 ms 5464 KB Output is correct
3 Correct 1 ms 5468 KB Output is correct
4 Correct 1 ms 5468 KB Output is correct
5 Correct 1 ms 5464 KB Output is correct
6 Correct 80 ms 19796 KB Output is correct

Subtask #3
21.0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 5976 KB Output is correct
2 Correct 1 ms 5468 KB Output is correct
3 Correct 1 ms 5468 KB Output is correct
4 Correct 2 ms 5468 KB Output is correct
5 Correct 3 ms 5724 KB Output is correct
6 Correct 1 ms 5468 KB Output is correct
7 Correct 2 ms 5724 KB Output is correct
8 Correct 1 ms 5468 KB Output is correct
9 Correct 2 ms 5468 KB Output is correct
10 Correct 2 ms 5808 KB Output is correct
11 Correct 1 ms 5464 KB Output is correct
12 Correct 2 ms 5724 KB Output is correct
13 Correct 1 ms 5468 KB Output is correct
14 Correct 1 ms 5468 KB Output is correct
15 Correct 2 ms 5468 KB Output is correct
16 Correct 2 ms 5468 KB Output is correct
17 Correct 44 ms 14224 KB Output is correct
18 Correct 35 ms 12804 KB Output is correct
19 Correct 1 ms 5468 KB Output is correct
20 Correct 1 ms 5468 KB Output is correct
21 Correct 1 ms 5468 KB Output is correct
22 Correct 1 ms 5720 KB Output is correct
23 Correct 84 ms 19708 KB Output is correct

Subtask #4
8.4 / 24.0

# Verdict Execution time Memory Grader output
1 Partially correct 1 ms 5468 KB Output is partially correct
2 Partially correct 3 ms 5864 KB Output is partially correct
3 Correct 46 ms 10580 KB Output is correct
4 Correct 68 ms 14420 KB Output is correct
5 Partially correct 4 ms 5724 KB Output is partially correct
6 Correct 3 ms 5724 KB Output is correct
7 Correct 1 ms 5468 KB Output is correct
8 Correct 1 ms 5652 KB Output is correct
9 Correct 1 ms 5464 KB Output is correct
10 Correct 2 ms 5724 KB Output is correct
11 Correct 4 ms 5808 KB Output is correct
12 Partially correct 4 ms 5724 KB Output is partially correct
13 Partially correct 4 ms 5724 KB Output is partially correct
14 Correct 3 ms 5724 KB Output is correct
15 Correct 3 ms 5980 KB Output is correct
16 Partially correct 2 ms 5724 KB Output is partially correct
17 Correct 1 ms 5468 KB Output is correct
18 Correct 3 ms 5680 KB Output is correct
19 Correct 2 ms 5724 KB Output is correct
20 Correct 97 ms 11324 KB Output is correct
21 Partially correct 132 ms 15496 KB Output is partially correct
22 Correct 3 ms 5720 KB Output is correct
23 Correct 2 ms 5468 KB Output is correct
24 Correct 1 ms 5468 KB Output is correct
25 Partially correct 2 ms 5724 KB Output is partially correct
26 Partially correct 3 ms 5724 KB Output is partially correct
27 Correct 68 ms 14092 KB Output is correct
28 Correct 90 ms 14512 KB Output is correct
29 Correct 2 ms 5468 KB Output is correct
30 Correct 194 ms 16812 KB Output is correct
31 Partially correct 1 ms 5464 KB Output is partially correct
32 Correct 95 ms 14976 KB Output is correct
33 Correct 64 ms 10836 KB Output is correct
34 Correct 33 ms 11344 KB Output is correct
35 Partially correct 2 ms 5724 KB Output is partially correct
36 Correct 77 ms 13652 KB Output is correct
37 Partially correct 175 ms 16212 KB Output is partially correct
38 Correct 2 ms 5720 KB Output is correct
39 Correct 133 ms 13652 KB Output is correct
40 Partially correct 3 ms 5724 KB Output is partially correct
41 Correct 188 ms 16884 KB Output is correct
42 Correct 90 ms 14932 KB Output is correct
43 Correct 1 ms 5464 KB Output is correct
44 Correct 4 ms 5724 KB Output is correct
45 Partially correct 3 ms 5724 KB Output is partially correct
46 Correct 27 ms 10324 KB Output is correct

Subtask #5
0.0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 5468 KB Output is correct
2 Correct 1 ms 5468 KB Output is correct
3 Correct 2 ms 5468 KB Output is correct
4 Correct 1 ms 5468 KB Output is correct
5 Correct 1 ms 5468 KB Output is correct
6 Correct 1 ms 5468 KB Output is correct
7 Correct 37 ms 10460 KB Output is correct
8 Correct 1 ms 5464 KB Output is correct
9 Correct 2 ms 5464 KB Output is correct
10 Correct 1 ms 5468 KB Output is correct
11 Correct 1 ms 5468 KB Output is correct
12 Correct 1 ms 5464 KB Output is correct
13 Correct 80 ms 19796 KB Output is correct
14 Correct 3 ms 5976 KB Output is correct
15 Correct 1 ms 5468 KB Output is correct
16 Correct 1 ms 5468 KB Output is correct
17 Correct 2 ms 5468 KB Output is correct
18 Correct 3 ms 5724 KB Output is correct
19 Correct 1 ms 5468 KB Output is correct
20 Correct 2 ms 5724 KB Output is correct
21 Correct 1 ms 5468 KB Output is correct
22 Correct 2 ms 5468 KB Output is correct
23 Correct 2 ms 5808 KB Output is correct
24 Correct 1 ms 5464 KB Output is correct
25 Correct 2 ms 5724 KB Output is correct
26 Correct 1 ms 5468 KB Output is correct
27 Correct 1 ms 5468 KB Output is correct
28 Correct 2 ms 5468 KB Output is correct
29 Correct 2 ms 5468 KB Output is correct
30 Correct 44 ms 14224 KB Output is correct
31 Correct 35 ms 12804 KB Output is correct
32 Correct 1 ms 5468 KB Output is correct
33 Correct 1 ms 5468 KB Output is correct
34 Correct 1 ms 5468 KB Output is correct
35 Correct 1 ms 5720 KB Output is correct
36 Correct 84 ms 19708 KB Output is correct
37 Incorrect 1 ms 5468 KB Output isn't correct
38 Halted 0 ms 0 KB -