Submission #682115

#	Time	Username	Problem	Language	Result	Execution time	Memory
682115		opPO	Longest beautiful sequence (IZhO17_subsequence)	C++17	0 / 100	1641 ms	262144 KiB

subsequence

#pragma GCC optimize("O3,unroll-loops")
#include <bits/stdc++.h>

using namespace std;

#define int long long
#define f first
#define s second
#define pb push_back
#define ld long double
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define vec vector

using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;

mt19937_64 gen(chrono::steady_clock::now().time_since_epoch().count());
const ld eps = 1e-6;
const int mod = 998244353;
const int oo = 2e9;
const ll OO = 2e18;
const int N = 250001;

void solve()
{
    int n;
    cin >> n;
    vec<int> a(n + 1);
    for (int i = 1; i <= n; i++) cin >> a[i];
    vec<int> k(n + 1);
    for (int i = 1; i <= n; i++) cin >> k[i];
    vec<int> dp(n + 1, 1);
    vec<int> fr(n + 1, -1);
    vec<int> last(256, -1);
    for (int i = 1; i <= n; i++)
    {
        if (n <= 5000)
        {
            for (int j = 1; j < i; j++)
            {
                int x = a[j] & a[i];
                if (__builtin_popcount(x) == k[i] && dp[j] + 1 > dp[i])
                {
                    dp[i] = dp[j] + 1;
                    fr[i] = j;
                }
            }
        }
        else
        {
            for (int y = 0; y < 256; y++)
            {
                if (last[y] == -1) continue;
                int x = y & a[i];
                if (__builtin_popcount(x) == k[i] && dp[last[y]] + 1 > dp[i])
                {
                    dp[i] = dp[last[y]] + 1;
                    fr[i] = last[y];
                }
            }
            if (last[a[i]] == -1 || dp[i] > dp[last[a[i]]]) last[a[i]] = i;
        }
    }
    vec<int> ans;
    int best = 1;
    for (int i = 2; i <= n; i++) if (dp[i] > dp[best]) best = i;
    while (best != -1)
    {
        ans.pb(best);
        best = fr[best];
    }
    reverse(all(ans));
    cout << sz(ans) << "\n";
    for (int &x : ans) cout << x << " ";
}

int32_t main()
{
    freopen("subsequence.in", "r", stdin);
    freopen("subsequence.out", "w", stdout);
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    solve();
    return 0;
}

Compilation message (stderr)

subsequence.cpp: In function 'int32_t main()':
subsequence.cpp:82:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   82 |     freopen("subsequence.in", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
subsequence.cpp:83:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   83 |     freopen("subsequence.out", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 7
• Subtask 2: 0 / 16
• Subtask 3: 0 / 17
• Subtask 4: 0 / 60