Submission #549506

#	Time	Username	Problem	Language	Result	Execution time	Memory
549506		xdfactor2034	Doktor (COCI17_doktor)	C++17	0 / 100	94 ms	15008 KiB

doktor

#include<bits/stdc++.h>
using namespace std;
const int maxn = 5e5+5;
int ar[maxn], lk[maxn];
int wl[maxn], wr[maxn];
int dpl[maxn], dpr[maxn];
#define cerr while(0) cerr
#define INF 1000000000
signed main() {
	#ifndef cerr
	freopen("a.in", "r", stdin);
	freopen("a.out", "w", stdout);
	#endif
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	int N;
	cin >> N;
	for(int i = 1; i <= N; i++) cin >> ar[i], lk[ar[i]] = i;
	for(int i = 1; i <= N; i++) {
		int score = i - ar[i];
		if(score >= 0) wl[i] = score, wr[i] = -INF; else wl[i] = -INF, wr[i] = -score;
	}

	for(int i = 1; i <= N; i++) cerr << "w " << wl[i] << ' ' << wr[i] << '\n';
	int glob = 0;
	for(int i = 1; i <= N; i++) if(ar[i] == i) glob++;
	for(int i = 1; i <= N; i++) dpl[i] = (wl[i-1] + 2 == wl[i]) ? dpl[i-1]+1 : 1;
	for(int i = N; i >= 1; i--) dpr[i] = (wr[i+1] + 2 == wl[i]) ? dpr[i+1]+1 : 1;

	for(int i = 1; i <= N; i++) cerr << dpl[i] << ' ' << dpr[i] << '\n';
	int bg = 1;
	int res = 0;
	int a = -1, b = -1;
	for(int i = 1; i <= N; i++) {
		if(dpl[i] >= dpl[i+1]) {
			int old = 0;
			int first = bg - (i - bg);
			assert(first >= 1);
			for(int j = first; j <= i; j++) if(ar[j] == j) old++;
			glob -= old;
			reverse(ar+first, ar+i+1);
			int next = 0;
			for(int j = first; j <= i; j++) if(ar[j] == j) next++;
			if(glob + next > res) res = glob+next, a = first, b = i;
			glob += old;
			bg = i+1;
			reverse(ar+first, ar+i+1);
		}
	}
	int en = N;
	for(int i = N; i >= 1; i--) {
		if(dpr[i] >= dpr[i-1]) {
			int old = 0;
			int last = en+(en-i);
			assert(last <= N);
			for(int j = i; j <= last; j++) if(ar[j] == j) old++;
			glob -= old;
			reverse(ar+i, ar+last+1);
			int next = 0;
			for(int j = i; j <= last; j++) if(ar[j] == j) next++;
			if(glob + next > res) res = glob+next, a = i, b = last;
			glob += old;
			en = i-1;
			reverse(ar+i, ar+last+1);
		}
	}
	cerr << glob << '\n';
	cout << ar[a] << ' ' << ar[b] << '\n'; 
}

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