제출 #951328

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
951328		steveonalex	서열 (APIO23_sequence)	C++17	28 / 100	2062 ms	19100 KiB

sequence

#include <bits/stdc++.h>
#include "sequence.h"

using namespace std;

typedef long long ll;
typedef unsigned long long ull;

#define MASK(i) (1LL << (i))
#define GETBIT(mask, i) (((mask) >> (i)) & 1)
#define ALL(v) (v).begin(), (v).end()

ll max(ll a, ll b){return (a > b) ? a : b;}
ll min(ll a, ll b){return (a < b) ? a : b;}

ll LASTBIT(ll mask){return (mask) & (-mask);}
int pop_cnt(ll mask){return __builtin_popcountll(mask);}
int ctz(ll mask){return __builtin_ctzll(mask);}
int logOf(ll mask){return __lg(mask);}

mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rngesus(ll l, ll r){return l + (ull) rng() % (r - l + 1);}

template <class T1, class T2>
    bool maximize(T1 &a, T2 b){
        if (a < b) {a = b; return true;}
        return false;
    }

template <class T1, class T2>
    bool minimize(T1 &a, T2 b){
        if (a > b) {a = b; return true;}
        return false;
    }

template <class T>
    void printArr(T& container, char separator = ' ', char finish = '\n'){
        for(auto item: container) cout << item << separator;
        cout << finish;
    }


template <class T>
    void remove_dup(vector<T> &a){
        sort(ALL(a));
        a.resize(unique(ALL(a)) - a.begin());
    }

namespace Sub2{
    struct FenwickTree{
        int n;
        vector<int> a;

        FenwickTree(int _n){
            n = _n;
            a.resize(n+1);
        }

        void update(int i, int v){
            while(i <= n){
                a[i] += v;
                i += LASTBIT(i);
            }
        }

        int get(int i){
            int ans = 0;
            while(i > 0){
                ans += a[i];
                i -= LASTBIT(i);
            }
            return ans;
        }

        int binaryLift(int v){
            int idx = 0, p = MASK(logOf(n));
            while(p > 0){
                if (idx + p <= n && v - a[idx + p] > 0){
                    idx += p;
                    v -= a[idx];
                }
                p >>= 1;
            }
            return idx + 1;
        }
    };

    int solve(int n, vector<int> a){
        int ans = 0;
        for(int i = 0; i<n; ++i){
            FenwickTree bit(n);
            vector<int> cnt(n+1);
            for(int j = i; j<n; ++j){
                bit.update(a[j], 1);
                cnt[a[j]]++;
                int mid = (j - i) / 2 + 1;
                maximize(ans, cnt[bit.binaryLift(mid)]);
                if (mid * 2 == (j - i + 1)){
                    maximize(ans, cnt[bit.binaryLift(mid + 1)]);
                }
            }
        }

        return ans;
    }
}


namespace Sub3{
    struct FenwickTree{
        int n;
        vector<int> a;

        FenwickTree(int _n){
            n = _n;
            a.resize(n+1);
        }

        void update(int i, int v){
            while(i <= n){
                a[i] += v;
                i += LASTBIT(i);
            }
        }

        int get(int i){
            int ans = 0;
            while(i > 0){
                ans += a[i];
                i -= LASTBIT(i);
            }
            return ans;
        }

        int binaryLift(int v){
            int idx = 0, p = MASK(logOf(n));
            while(p > 0){
                if (idx + p <= n && v - a[idx + p] > 0){
                    idx += p;
                    v -= a[idx];
                }
                p >>= 1;
            }
            return idx + 1;
        }
    };

    bool check(vector<int> a){
        for(int i: a) if (i > 3) return 0;
        return 1;
    }

    int edging(int n, vector<int> a){
        int ans = 0;
        vector<array<int, 3>> pref(n+1, {{0, 0, 0}});
        a.insert(a.begin(), -1);

        for(int i = 1; i<=n; ++i){
            pref[i] = pref[i-1];
            if (a[i] == 1) pref[i][0]++;

            if (a[i] < 1) pref[i][1]++;
            else pref[i][1]--;
            if (a[i] <= 1) pref[i][2]++;
            else pref[i][2]--;
        }
        for(int i = 0; i<=n; ++i)
        for(int j = i + 1; j<=n; ++j){
            if (pref[j][2] >= pref[i][2] && pref[j][1] < pref[i][1]) 
                maximize(ans, pref[j][0] - pref[i][0]);
        }
        return ans;
    }

    int solve(int n, vector<int> a){
        int ans = 0;
        for(int i = 1; i<=3; ++i){
            vector<int> b = a;
            for(int &j: b){
                if (j < i) j = 0;
                else if (j == i) j = 1;
                else j = 2;
            }
            maximize(ans, edging(n, b));
        }

        return ans;
    }
}

int sequence(int n, vector<int> a) {
    if (Sub3::check(a)) return Sub3::solve(n, a);
    if (n <= 5000) return Sub2::solve(n, a);
    return 0;
}


// int main(void){
//     ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);

//     int n; cin >> n;
//     vector<int> a(n);
//     for(int i = 0; i<n; ++i) cin >> a[i];

//     cout << sequence(n, a) << "\n";

//     return 0;
// }

• Subtask 1: 11 / 11
• Subtask 2: 17 / 17
• Subtask 3: 0 / 7
• Subtask 4: 0 / 12
• Subtask 5: 0 / 13
• Subtask 6: 0 / 22
• Subtask 7: 0 / 18