Submission #975159

#	Time	Username	Problem	Language	Result	Execution time	Memory
975159		LOLOLO	Paths (BOI18_paths)	C++14	100 / 100	347 ms	97184 KiB

paths

#include <bits/stdc++.h>
#define ll long long
using namespace std;
 
#define           f     first
#define           s     second
#define           pb    push_back
#define           ep    emplace
#define           eb    emplace_back
#define           lb    lower_bound
#define           ub    upper_bound
#define       all(x)    x.begin(), x.end()
#define      rall(x)    x.rbegin(), x.rend()
#define   uniquev(v)    sort(all(v)), (v).resize(unique(all(v)) - (v).begin())
#define     mem(f,x)    memset(f , x , sizeof(f))
#define        sz(x)    (int)(x).size()
#define  __lcm(a, b)    (1ll * ((a) / __gcd((a), (b))) * (b))
#define          mxx    *max_element
#define          mnn    *min_element
#define    cntbit(x)    __builtin_popcountll(x)
#define       len(x)    (int)(x.length())
 
const int N = 3e5 + 100;
ll dp[N][(1 << 5)];
int a[N];
vector <int> ed[N];

ll dfs(int u, int mask) {
    if (mask == 0)
        return 1;

    if (dp[u][mask] != -1)
        return dp[u][mask];

    ll ans = 0;
    for (auto x : ed[u]) {
        if ((a[x] & mask) == a[x]) {
            ans += dfs(x, mask ^ a[x]);
        }
    }

    return dp[u][mask] = ans;
}

ll solve() {
    int n, m, k;
    cin >> n >> m >> k;

    for (int i = 1; i <= n; i++) {
        cin >> a[i]; 
        a[i]--;
        a[i] = (1 << a[i]);
    }

    for (int i = 0; i < m; i++) {
        int a, b;
        cin >> a >> b;
        ed[a].pb(b);
        ed[b].pb(a);
    }

    ll ans = 0;
    for (int i = 1; i <= n; i++) {
        for (int mask = 1; mask < (1 << k); mask++) {
            if ((a[i] & mask) == a[i] && cntbit(mask) > 1) {
                ans += dfs(i, mask ^ a[i]);
            }
        }
    }

    return ans;
}

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

    mem(dp, -1)
    ;
    int t = 1;
    //cin >> t;
    while (t--) {
        cout << solve() << '\n';
    }

    return 0;
}



 

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