#include "gondola.h"
#include <iostream>
#include <vector>
#include <cassert>
#include <set>
#include <algorithm>
using namespace std;
#define rep(i, n) for (int i=0; i<(n); i++)
#define all(x) x.begin(), x.end()
int A[100000], cur[100000];
int cnt[250000];
bool glock;
int valid(int N, int inputSeq[]) {
rep(i, 250000) cnt[i] = 0;
rep(i, N) A[i] = inputSeq[i]-1;
rep(i, N) cnt[A[i]]++;
rep(i, 250000) if (cnt[i] > 1) return 0;
int base = -1;
rep(i, N) if (A[i] < N) base = (A[i]-i+N)%N;
rep(i, N) cur[i] = (i+max(0,base))%N;
glock = false;
if (base == -1) return 1;
glock = true;
rep(i, N) if (A[i] < N && A[i] != cur[i]) return 0;
return 1;
}
//----------------------
int rev[250000];
set<int> unused;
int replacement(int N, int gondolaSeq[], int replacementSeq[]) {
assert(valid(N, gondolaSeq));
rep(i, N) rev[A[i]] = i;
rep(i, N) if (A[i] >= N) unused.insert(i);
int m = *max_element(A, A+N);
int c = 0;
for (int i=N; i<=m; i++) {
int p = -1;
if (cnt[i]) {
p = rev[i];
unused.erase(rev[i]);
}
else p = *unused.begin();
replacementSeq[c++] = cur[p]+1;
cur[p] = i;
}
return c;
}
//----------------------
int countReplacement(int N, int inputSeq[]) {
if (valid(N, inputSeq) == 0) return 0;
return -3;
}
