#include "choreography.h"
#include <vector>

int x0 = 0, x1 = 0, i0 = 0, i1 = 0, n;
bool s = false;
std::vector<int> p, inv;

void init(int N, std::vector<int> P){
	n = N;
	p = P;
	inv.resize(N);
	for(int i = 0; i < N; i++){
		inv[P[i]] = i;
	}
}

void move_right(int K){
	x0 += + K;
    x1 += + K;
	if(x0 >= n) x0 -= n;
	if(x1 >= n) x1 -= n;
}

void move_left(int K){
	move_right(n - K);
}

void swap_places(){
	x0 += x0&1 ? -1 : 1;
    x1 += x1&1 ? 1 : -1;
    if(x1 < 0) x1 += n;
    if(x1 >= n) x1 -= n; 
}

void move_around(){
	s = !s;
	std::swap(x0, i0);
	std::swap(x1, i1);
}

int get_position(int D){
	int i = (D-i0)%2 == 0 ? D - i0 : D - i1;
	if(i < 0) i += n;
	int x = s ? p[i] : inv[i];
	int ans = x&1 ? x + x1 : x + x0; 
	return ans < n ? ans : ans - n;
}