#include "gondola.h"
#include <bits/stdc++.h>
using namespace std;
int valid(int n, int inputSeq[])
{
set<int> seen;
for (int i = 0; i < n; ++i)
if (seen.count(inputSeq[i]))
return 0;
else
seen.insert(inputSeq[i]);
int start = -1;
for (int i = 0; i < n; ++i)
if (inputSeq[i] <= n)
{
start = i;
break;
}
if (start != -1)
{
int base = inputSeq[start];
for (int i = 0; i < n; ++i)
{
int expected = (base + i - start) % n;
if (expected <= 0)
expected += n;
if (inputSeq[i] <= n && inputSeq[i] != expected)
return 0;
}
}
int nextReplacement = n + 1;
for (int i = 0; i < n; ++i)
if (inputSeq[i] > n)
if (inputSeq[i] < nextReplacement)
return 0;
else
nextReplacement = inputSeq[i] + 1;
return 1;
}
int replacement(int n, int gondolaSeq[], int replacementSeq[])
{
int start = -1;
for (int i = 0; i < n; ++i)
if (gondolaSeq[i] <= n)
{
start = i;
break;
}
int M = 0;
for (int i = 0; i < n; ++i)
M = max(M, gondolaSeq[i]);
int totalBreaks = M - n;
if (start == -1)
{
for (int i = 0; i < totalBreaks; ++i)
replacementSeq[i] = i + 1;
return totalBreaks;
}
int base = gondolaSeq[start];
vector<pair<int, int>> chains; // {final replacement, current head}
for (int i = 0; i < n; ++i)
{
int expected = (base + i - start) % n;
if (expected <= 0)
expected += n;
if (gondolaSeq[i] > n)
chains.push_back({gondolaSeq[i], expected});
}
sort(chains.begin(), chains.end());
int idx = 0;
int nextReplacement = n + 1;
while (chains.size())
{
bool finished = false;
for (int i = 0; i < (int)chains.size(); ++i)
if (chains[i].first == nextReplacement)
{
replacementSeq[idx++] = chains[i].second;
chains.erase(chains.begin() + i);
finished = true;
break;
}
if (finished)
{
++nextReplacement;
continue;
}
bool extended = false;
for (auto &c : chains)
if (c.first > nextReplacement)
{
replacementSeq[idx++] = c.second;
c.second = nextReplacement++;
extended = true;
break;
}
// impossible case
if (!extended)
break;
}
return idx;
}
int countReplacement(int n, int inputSeq[])
{
return -3;
}
