Submission #473373

#	Time	Username	Problem	Language	Result	Execution time	Memory
473373		_L__	Doktor (COCI17_doktor)	C++17	80 / 100	570 ms	42148 KiB

doktor

// This code is written by _L__
#include <bits/stdc++.h>
using namespace std;
#define endl '\n'
#define F_word ios_base::sync_with_stdio(false), cin.tie(NULL), cout.tie(NULL);
typedef long long ll;
typedef long double ld;
const ll mod = 1e9+7, N = 2e5+13, inf = 1e9+1;
const ld E = 1e-6;
#define ff first
#define ss second
 
int main(void){
    F_word;
    ll n; cin >> n;
    ll a[n+2] = {}, doc[n+4] = {}, pref[n+3] = {};
    for(ll i = 1; i <= n; ++i){
        cin >> a[i]; doc[a[i]] = a[i]-i; pref[i] += pref[i-1]; pref[i] += (doc[a[i]] == 0);
    }
    a[0] = 1;
    if(n <= 500){
        ll sum = 0, ans1 = 1, ans2 = 1;
        for(int i = 1; i <= n; ++i){
            for(int j = i; j <= n; ++j){
                reverse(a+i, a+j+1);
                ll x = 0; for(int k = 1; k <= n; ++k) x += (a[k] == k);
                if(x >= sum){
                    ans1 = i, ans2 = j, sum = x;
                }
                reverse(a+i, a+j+1);
            }
        }
        cout << a[ans1] << ' ' << a[ans2] << endl;
        return 0;
    }
    map<ll, ll> freq_odd, freq_even;
    for(ll i = 1; i <= n; ++i){
        if(!(doc[a[i]]%2))
            freq_odd[(i+a[i])/2]++;
        if(doc[a[i]]%2)
            freq_even[(a[i]+i)/2]++;
    }
    ll ans_odd = 0, tar = 0, ans_even = 0;
    for(auto u: freq_odd)
        if(u.ss >= tar)
            {tar = u.ss, ans_odd = u.ff;}
    tar = 0;
    for(auto u: freq_even)
        if(u.ss >= tar)
            {tar = u.ss, ans_even = u.ff;}
    if(ans_even == 0 && ans_odd == 0)return cout << 1 << ' ' << 1 << endl, 0;
    if(ans_even == 0){
        ll a_1 = ans_odd, a_2 = ans_odd, sum = 0, i = ans_odd-1, j = ans_odd+1, total = (a[a_1] == a_1);
        while(i > 0 && j <= n){
            ll c = (a[i]+i)/2; if(c==ans_odd)++total;
            c = (a[j]+j)/2; if(c == ans_odd)++total;
            ll x = total+pref[i-1]+(pref[n]-pref[j]);
            if(x >= sum){
                a_1 = i, a_2 = j; sum = x;
            }
            ++j; --i;
        }
        cout << a[a_1] << ' ' << a[a_2] << endl;
    } else if(ans_odd == 0){
        ll a_3 = ans_even, a_4 = ans_even+1, sum1 = 0, i = a_3-1, j = a_4+1, total = (a[a_3] == a_4) + (a[a_4] == a_3);
        while(i > 0 && j <= n){
            ll c = (a[i]+i)/2; if(c==ans_even)++total;
            c = (a[j]+j)/2; if(c == ans_even)++total;
            ll x = total+pref[i-1]+(pref[n]-pref[j]);
            if(x >= sum1){
                a_3 = i, a_4 = j; sum1 = x;
            }
            ++j; --i;   
        }
        cout << a[a_3] << ' ' << a[a_4] << endl;
    } else {
        ll a_1 = ans_odd, a_2 = ans_odd, sum = 0, i = ans_odd-1, j = ans_odd+1, total = (a[a_1] == a_1);
        while(i > 0 && j <= n){
            ll c = (a[i]+i)/2; if(c==ans_odd)++total;
            c = (a[j]+j)/2; if(c == ans_odd)++total;
            ll x = total+pref[i-1]+(pref[n]-pref[j]);
            if(x >= sum){
                a_1 = i, a_2 = j; sum = x;
            }
            ++j; --i;
        }
        ll a_3 = ans_even, a_4 = ans_even+1, sum1 = 0; i = a_3-1, j = a_4+1, total = (a[a_3] == a_4) + (a[a_4] == a_3);
        while(i > 0 && j <= n){
            ll c = (a[i]+i)/2; if(c==ans_even)++total;
            c = (a[j]+j)/2; if(c == ans_even)++total;
            ll x = total+pref[i-1]+(pref[n]-pref[j]);
            if(x >= sum1){
                a_3 = i, a_4 = j; sum1 = x;
            }
            ++j; --i;   
        }
        if(sum >= sum1) cout << a[a_1] << ' ' << a[a_2] << endl;
        else cout << a[a_3] << ' ' << a[a_4] << endl;
    }
} 

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 0 / 10
• Subtask 7: 10 / 10
• Subtask 8: 0 / 10
• Subtask 9: 10 / 10
• Subtask 10: 10 / 10