Submission #334780

#	Time	Username	Problem	Language	Result	Execution time	Memory
334780		limabeans	Longest beautiful sequence (IZhO17_subsequence)	C++17	100 / 100	5849 ms	52588 KiB

subsequence

#include <bits/stdc++.h>
using namespace std;

template<typename T>
void out(T x) { cout << x << endl; exit(0); }
#define watch(x) cout << (#x) << " is " << (x) << endl





using ll = long long;


const int maxn = 1e6 + 5;



int n;
int a[maxn];
int k[maxn];

int dp[maxn], p[maxn];
int store[1024][1024][12];

int count(int mask) {
    return __builtin_popcount(mask);
}

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

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


    //store[mask][mask2][cnt]: best index if our top10bits=mask, and we merge with someone whose lower10bits=mask2,
    //                         and we need cnt bits in the top10

    for (int i=1; i<=n; i++) {
	int l = (a[i]>>10);
	int r = (a[i]&1023);
	//qry
	int best = 0;
	for (int mask=0; mask<1024; mask++) {
	    int need = k[i] - count(mask&r);
	    if (need>10 || need<0) continue;
	    if (dp[best]<dp[store[l][mask][need]]) {
		best=store[l][mask][need];
	    }
	}
	dp[i]=1+dp[best];
	p[i]=best;

	//insert
	for (int mask=0; mask<1024; mask++) {
	    int cnt = count(mask&l);
	    if (dp[store[mask][r][cnt]] < dp[i]) {
		store[mask][r][cnt] = i;
	    }
	}
    }


    int at = 1;
    for (int i=1; i<=n; i++) {
	if (dp[at]<dp[i]) at=i;
    }

    vector<int> ans;
    while (at) {
	ans.push_back(at);
	at=p[at];
    }

    sort(ans.begin(),ans.end());
    cout<<ans.size()<<endl;
    for (int i: ans) cout<<i<<" ";
    cout<<endl;    
    return 0;
}

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