Submission #988958

#	Time	Username	Problem	Language	Result	Execution time	Memory
988958		emptypringlescan	Archery (IOI09_archery)	C++17	31 / 100	2094 ms	2140 KiB

archery

#include <bits/stdc++.h>
using namespace std;
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,popcnt,lzcnt")
int n;
long long r;
int arr[200005],brr[200005],at;
int calc(){
	if(arr[at]==1) return 1;
	for(int i=0; i<2*n; i++) brr[i]=arr[i];
	int ex[n];
	memset(ex,0,sizeof(ex));
	int rnd=min(n,400);
	for(int k=0; k<rnd; k++){
		for(int j=0; j<n; j++) ex[j]=0;
		if(brr[1]>brr[0]) ex[0]=1;
		for(int j=1; j<n; j++){
			if(brr[j<<1|1]<brr[j<<1]) ex[j]=1;
		}
		swap(brr[ex[0]],brr[(n-1)<<1|ex[n-1]]);
		for(int i=0; i<n-2; i++){
			swap(brr[i<<1|ex[i]],brr[(i+1)<<1|ex[i+1]]);
		}
	}
	int cur=0;
	for(int i=0; i<2*n; i++){
		if(arr[at]==brr[i]) cur=i/2;
	}
	if(arr[at]>n) return cur+1;
	cur-=r-rnd;
	cur%=n;
	if(cur<0) cur+=n;
	return cur+1;
}
int32_t main(){
	ios::sync_with_stdio(0);
	cin.tie(0);
	cin >> n >> r;
	for(int i=0; i<2*n; i++){
		cin >> arr[i];
	}
	for(int i=0; i<2*n-1; i++) swap(arr[i],arr[i+1]);
	at=2*n-1;
	pair<int,int> ans={1e8,-1};
	for(int i=2*n-1; i>=max(0,2*n-4000); i-=2){
		int x=calc();
		//cout << i << ' ' << x << '\n';
		if(x<ans.first) ans={x,i};
		if(i){
			at--;
			swap(arr[i],arr[i-1]);
			at--;
			swap(arr[i-1],arr[i-2]);
		}
	}
	cout << ans.second/2+1;
}

• Subtask 1: 5 / 6
• Subtask 2: 26 / 94