Submission #1167170

#	Time	Username	Problem	Language	Result	Execution time	Memory
1167170		SmuggingSpun	Longest beautiful sequence (IZhO17_subsequence)	C++20	100 / 100	2530 ms	178160 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] << " ";
        }
    }
}
namespace sub3{
    void solve(){
        vector<int>dp(n + 1, 1), trace(n + 1, dp[0] = 0), max_dp_pos(256, 0);
        for(int i = 1; i <= n; i++){
            for(int j = 0; j < 256; j++){
                if(max_dp_pos[j] != 0 && __builtin_popcount(j & a[i]) == k[i] && maximize(dp[i], dp[max_dp_pos[j]] + 1)){
                    trace[i] = max_dp_pos[j];
                }
            }
            if(dp[i] > dp[max_dp_pos[a[i]]]){
                max_dp_pos[a[i]] = i;
            }
        }
        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] << " ";
        }
    }
}
namespace sub4{
    const int SIZE = 1 << 10;
    pair<int, int>dp[SIZE][SIZE][21];
    int trace[lim], bit_count[SIZE][SIZE];
    void solve(){
        for(int i = 0; i < SIZE; i++){
            for(int j = i; j < SIZE; j++){
                bit_count[i][j] = bit_count[j][i] = __builtin_popcount(i & j);
                fill(dp[i][j], dp[i][j] + 21, make_pair(-1, -1));
            }
        }
        iota(trace + 1, trace + n + 1, 1);
        int best_i, best_ans = 0;
        for(int i = 1; i <= n; i++){
            int L = a[i] & (SIZE - 1), R = a[i] >> 10, ans = 1, ans_end = i;
            for(int j = 0; j < SIZE; j++){
                int need_k = k[i] - bit_count[L][j];
                if(need_k > -1 && maximize(ans, dp[j][R][need_k].first + 1)){
                    trace[i] = dp[j][R][need_k].second;
                }
            }
            if(maximize(best_ans, ans)){
                best_i = i;
            }
            for(int j = 0; j < SIZE; j++){
                auto& [dp_ans, dp_end] = dp[L][j][bit_count[R][j]];
                if(maximize(dp_ans, ans)){
                    dp_end = i;
                }
            }
        }
        vector<int>ans;
        while(best_i != trace[best_i]){
            ans.emplace_back(best_i);
            best_i = trace[best_i];
        }
        cout << best_ans << "\n" << best_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();
    }
    else if(*max_element(a + 1, a + n + 1) < 256){
        sub3::solve();
    }
    else{
        sub4::solve();
    }
}

Compilation message (stderr)

subsequence.cpp: In function 'int main()':
subsequence.cpp:146:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  146 |                 freopen(taskname".inp", "r", stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~

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