Submission #1167162

#	Time	Username	Problem	Language	Result	Execution time	Memory
1167162		SmuggingSpun	Longest beautiful sequence (IZhO17_subsequence)	C++20	23 / 100	33 ms	1132 KiB

subsequence

#include<bits/stdc++.h>
#define taskname "C"
using namespace std;
template<class T>bool maximize(T& a, T b){
    if(a < b){
        a = b;
        return true;
    }
    return false;
}
const int lim = 1e5 + 5;
int n, a[lim], k[lim];
namespace sub1{
    void solve(){
        int ans_mask = 0;
        for(int mask = (1 << n) - 1; mask > 0; mask--){
            if(__builtin_popcount(mask) > __builtin_popcount(ans_mask)){
                vector<int>p;
                for(int i = 0; i < n; i++){
                    if(1 << i & mask){
                        p.emplace_back(i + 1);
                    }
                }
                bool flag = true;
                for(int i = 1; i < p.size(); i++){
                    if(__builtin_popcount(a[p[i]] & a[p[i - 1]]) != k[p[i]]){
                        flag = false;
                        break;
                    }
                }
                if(flag){
                    ans_mask = mask;
                }
            }
        }
        cout << __builtin_popcount(ans_mask) << "\n";
        for(int i = 0; i < n; i++){
            if(1 << i & ans_mask){
                cout << i + 1 << " ";
            }
        }
    }
}
namespace sub2{
    void solve(){
        vector<int>dp(n + 1, 1), trace(n + 1, dp[0] = 0);
        for(int i = 1; i <= n; i++){
            for(int j = 1; j < i; j++){
                if(__builtin_popcount(a[i] & a[j]) == k[i] && maximize(dp[i], dp[j] + 1)){
                    trace[i] = j;
                }
            }
        }
        int I = 0;
        for(int i = 1; i <= n; i++){
            if(dp[i] > dp[I]){
                I = i;
            }
        }
        cout << dp[I] << "\n";
        vector<int>ans;
        while(I != 0){
            ans.emplace_back(I);
            I = trace[I];
        }
        for(int i = ans.size(); i > 0; ){
            cout << ans[--i] << " ";
        }
    }
}
int main(){
	ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	if(fopen(taskname".inp", "r")){
		freopen(taskname".inp", "r", stdin);
	}
    cin >> n;
    for(int i = 1; i <= n; i++){
        cin >> a[i];
    }
    for(int i = 1; i <= n; i++){
        cin >> k[i];
    }
    if(n <= 15){
        sub1::solve();
    }
    else if(n <= 5000){
        sub2::solve();
    }
}

Compilation message (stderr)

subsequence.cpp: In function 'int main()':
subsequence.cpp:74:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   74 |                 freopen(taskname".inp", "r", stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~

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