Submission #892691

#	Time	Username	Problem	Language	Result	Execution time	Memory
892691		NoLove	Longest beautiful sequence (IZhO17_subsequence)	C++14	23 / 100	41 ms	3932 KiB

subsequence

/**
 *    author : Lăng Trọng Đạt
 *    created: 25-12-2023 
**/
#include <bits/stdc++.h>
using namespace std;
#ifndef LANG_DAT
#define db(...) ;
#endif // LANG_DAT
#define int int64_t
#define mp make_pair
#define f first
#define s second
#define pb push_back
#define all(v) (v).begin(), (v).end()
using pii = pair<int, int>;

const int MAXN = 1e5 + 5;
const int B = 8;
int g[MAXN], k[MAXN], dp[MAXN], p[MAXN];
int bc[1 << B][1 << B];
// pii dp1[1 << 9]; // dp1[i][x]: LBS ending in x
int n;
int last = 0;

void sub1() {
    for (int i = 0; i < n; i++) {
        dp[i] = 1;
        p[i] = i;
    }
    for (int i = 1; i < n; i++) {
        for (int j = 0; j < i; j++) {
            if (__builtin_popcount(g[i] & g[j]) == k[i] && dp[j] + 1 > dp[i]) {
                dp[i] = dp[j] + 1;
                p[i] = j;
            }
        }
        if (dp[i] > dp[last]) {
            last = i;
        }
    }
    cout << dp[last] << "\n";
}
void sub3() {
    // memset(dp1, -1, sizeof(dp1));
    vector<pii> dp1(1 << B, {-1, -1});
    for (int i = 0; i < n; i++) {
        // dp1[g[i]].f = 1;
        // dp1[g[i]].s = -1;
        p[i] = i;
    }
    // for (int i = 0; i< n; i++) {
    //     if (dp1[g[i]].s == -1)
    //         dp1[g[i]].s = i;
    // }
    for (int i = 0; i < n; i++) {
        bool id = i & 1;
        if (dp1[g[i]].f == -1) {
            dp1[g[i]] = {1, i};
        }
        for (int j = 0; j < (1 << 8); j++) {
            if (bc[g[i]][j] == k[i] && dp1[j].f + 1 > dp1[g[i]].f && dp1[j].f != -1) {
                // db(g[i], j, dp1[j], dp1[g[i]].f)
                dp1[g[i]].f = dp1[j].f + 1;
                dp1[g[i]].s = i;
                p[i] = dp1[j].s;
            }
        }
        if (dp1[g[i]].f > dp1[g[last]].f) {
            db(i, g[i], dp1[g[i]].f)
            last = i;
        }
    }
    cout << dp1[g[last]].f << "\n";
}
int32_t main() {
    cin.tie(0)->sync_with_stdio(0);
    if (fopen("hi.inp", "r")) {
        freopen("hi.inp", "r", stdin);
//        freopen("hi.out", "w", stdout);
    } 

    // preprocess
    for (int i = 1; i < (1 << B); i++)
        for (int j = 1; j < (1 << B); j++)
            bc[i][j] = __builtin_popcount(i & j);
    std::cin >> n;
    for (int i = 0; i < n; i++) {
        std::cin >> g[i];
    }    
    for (int i = 0; i < n; i++) {
        std::cin >> k[i];
    }    

    if (n <= 5000) {
        sub1();
    } else {
        sub3();
    }
    db(last)
    vector<int> ans = {last};
    while (last != p[last]) {
        // db(last, dp1[last], p[last])
        last = p[last];
        ans.pb(last);
    }
    // cout << ans.size() << "\n";
    db(ans)
    for (int i = (int)ans.size() - 1; i >= 0; i--) {
        cout << ans[i] + 1 << " ";
    }
}

Compilation message (stderr)

subsequence.cpp: In function 'void sub3()':
subsequence.cpp:57:14: warning: unused variable 'id' [-Wunused-variable]
   57 |         bool id = i & 1;
      |              ^~
subsequence.cpp: In function 'int32_t main()':
subsequence.cpp:79:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   79 |         freopen("hi.inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

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