Submission #873900

#	Time	Username	Problem	Language	Result	Execution time	Memory
873900		noiaint	Paths (BOI18_paths)	C++17	100 / 100	487 ms	100560 KiB

paths

#include <bits/stdc++.h>
#define int long long

using namespace std;

#define file ""

#define mp make_pair
#define fi first
#define se second
#define all(x) x.begin(), x.end()

#define getbit(x, i) (((x) >> (i)) & 1)
#define bit(x) (1LL << (x))
#define popcount __builtin_popcountll

mt19937_64 rd(chrono::steady_clock::now().time_since_epoch().count());
int rand(int l, int r) {
    return l + rd() % (r - l + 1);
}

const int N = 3e5 + 5;
const int mod = (int)1e9 + 7; // 998244353;
const int lg = 25; // lg + 1
const int oo = 1e9;
const long long ooo = 1e18;

template<class X, class Y> bool mini(X &a, Y b) {
    return a > b ? (a = b, true) : false;
}
template<class X, class Y> bool maxi(X &a, Y b) {
    return a < b ? (a = b, true) : false;
}
void add(int &a, int b) {
    a += b;
    if (a >= mod) a -= mod;
    if (a < 0) a += mod;
}

int n, m, k;
vector<int> adj[N];
int a[N];
int f[N][1 << 5];

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(0);

    // freopen(file".inp", "r", stdin);
    // freopen(file".out", "w", stdout);

    cin >> n >> m >> k;
    for (int i = 0; i < n; ++i) {
        cin >> a[i];
        --a[i];
    }
    for (int i = 0; i < m; ++i) {
        int u, v;
        cin >> u >> v;
        --u, --v;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }
    for (int i = 0; i < n; ++i) {
        f[i][1 << a[i]] = 1;
    }
    for (int mask = 0; mask < bit(k); ++mask) {
        for (int i = 0; i < k; ++i) if (getbit(mask, i)) {
            for (int u = 0; u < n; ++u) {
                for (int v : adj[u]) if (a[v] == i) {
                    f[v][mask] += f[u][mask ^ bit(i)];
                }
            }
        }
    }

    int res = 0;
    for (int i = 0; i < n; ++i) for (int mask = 0; mask < bit(k); ++mask) {
        res += f[i][mask];
    }

    cout << res - n << '\n';

    return 0;
}

/*

*/

• Subtask 1: 23 / 23
• Subtask 2: 20 / 20
• Subtask 3: 27 / 27
• Subtask 4: 30 / 30