Submission #335769

#	Time	Username	Problem	Language	Result	Execution time	Memory
335769		534351	Praktični (COCI18_prakticni)	C++17	26 / 130	132 ms	12440 KiB

parkticni

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

using namespace std;
// using namespace __gnu_pbds;

// template<class T>
// using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

template<class T, class U>
void ckmin(T &a, U b)
{
    if (a > b) a = b;
}

template<class T, class U>
void ckmax(T &a, U b)
{
    if (a < b) a = b;
}

#define MP make_pair
#define PB push_back
#define LB lower_bound
#define UB upper_bound
#define fi first
#define se second
#define SZ(x) ((int) (x).size())
#define ALL(x) (x).begin(), (x).end()
#define FOR(i, a, b) for (auto i = (a); i < (b); i++)
#define FORD(i, a, b) for (auto i = (a) - 1; i >= (b); i--)

typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<pii> vpi;
typedef vector<pll> vpl;
typedef pair<pii, int> ppi;

const int MAXN = 100013;

int N, M;
vector<ppi> edge[MAXN];
bitset<MAXN> seen;
int parent[MAXN], val[MAXN], depth[MAXN];
bitset<MAXN> guys[32];
vi ord;

void dfs(int u)
{
    seen[u] = true;
    for (auto e : edge[u])
    {
        int v = e.se;
        if (seen[v]) continue;
        parent[v] = u;
        depth[v] = depth[u] + 1;
        val[v] = (val[u] ^ e.fi.fi);
        dfs(v);
    }
}
bool cmp(bitset<MAXN> a, bitset<MAXN> b) //is a < b.
{
    FORD(i, M, 0)
    {
        if (a[i] ^ b[i])
        {
            return (b[i]);
        }
    }
    return false;
}

int32_t main()
{
    cout << fixed << setprecision(12);
    cerr << fixed << setprecision(4);
    ios_base::sync_with_stdio(false); cin.tie(0);
    cin >> N >> M;
    FOR(i, 0, M)
    {
        int u, v, p;
        cin >> u >> v >> p;
        u--; v--;
        edge[u].PB({{p, i}, v});
        edge[v].PB({{p, i}, u});
    }
    parent[0] = N;
    dfs(0);
    FOR(u, 0, N)
    {
        for (auto e : edge[u])
        {
            int v = e.se;
            if (v == parent[u] || depth[v] >= depth[u]) continue;
            int c = (val[u] ^ val[v] ^ e.fi.fi);
            FORD(j, 31, 0)
            {
                if (c & (1 << j))
                {
                    guys[j][e.fi.se] = true;
                    // cerr << j << ' ' << e.fi.se << endl;
                }
            }
        }
    }
    FOR(i, 0, 31)
    {
        if (guys[i].none()) continue;
        ord.PB(i);
        val[i] = (1 << i);
    }
    sort(ALL(ord), [&](int a, int b)
    {
        return cmp(guys[a], guys[b]);
    });
    //just find which # is smaller.
    vi rem;
    int mask = 0;
    FOR(i, 0, SZ(ord))
    {
        FORD(j, SZ(rem), 0)
        {
            if (cmp(guys[ord[i]] ^ guys[rem[j]], guys[ord[i]]))
            {
                guys[ord[i]] ^= guys[rem[j]];
                val[rem[j]] ^= val[ord[i]];
            }
        }
        if (guys[ord[i]].none()) continue;
        FOR(j, 0, SZ(rem) + 1)
        {
            if (j == SZ(rem) || cmp(guys[rem[j]], guys[ord[i]]))
            {
                rem.insert(rem.begin() + j, ord[i]);
                break;
            }
        }
        //you have this bitset.
    }
    // for (int x : ord)
    // {
    //     cerr << x << ' ' << val[x] << endl;
    //     FOR(j, 0, M)
    //     {
    //         cerr << guys[x][j];
    //     }
    //     cerr << endl;
    // }
    int ans = 0;
    FOR(i, 0, 31) if (guys[i].any()) ans++;
    cout << ans << '\n';
    FOR(i, 0, 31)
    {
        if (guys[i].none()) continue;
        cout << val[i] << ' ' << guys[i].count();
        FOR(j, 0, M)
        {
            if (guys[i][j])
            {
                cout << ' ' << j + 1;
            }
        }
        cout << '\n';
    }
    return 0;
    // FOR(i, 0, 32)
    // {
    //     if (val[i] == 0) continue;
    //     cout << val[i] << ' ' << out[i].count();
    //     FOR(j, 0, M)
    //     {
    //         if (out[i][j])
    //         {
    //             cout << ' ' << j + 1;
    //         }
    //     }
    //     cout << '\n';
    // }
    //now we decide how to group them up. you have a bunch of bases.
    // cout << ans << '\n';
    // FOR(i, 0, ans)
    // {
    //     cout << res[i] << ' ' << SZ(guys[group[i]]);
    //     for (int x : guys[group[i]])
    //     {
    //         cout << ' ' << x + 1;
    //     }
    //     cout << '\n';
    // }
    return 0;
}

Compilation message (stderr)

parkticni.cpp: In function 'int32_t main()':
parkticni.cpp:122:9: warning: unused variable 'mask' [-Wunused-variable]
  122 |     int mask = 0;
      |         ^~~~

• Subtask 1: 13 / 13
• Subtask 2: 13 / 13
• Subtask 3: 0 / 13
• Subtask 4: 0 / 13
• Subtask 5: 0 / 13
• Subtask 6: 0 / 13
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• Subtask 10: 0 / 13