#include "souvenirs.h"
#include <bits/stdc++.h>
#ifdef LOCAL
#include "Debug.h"
#else
#define debug(...) 42
#endif
using namespace std;
int n;
vector<int> bought;
vector<long long> p;
pair<vector<int>, long long> buy(long long coins)
{
auto [ids, rem] = transaction(coins);
for (int i : ids)
bought[i]++;
return {ids, coins - rem};
}
void go(long long maxP)
{
auto [ids, cost] = buy(maxP);
int curId = ids[0], nextId = curId;
for (int i : ids)
if (i == nextId)
nextId++;
int len = nextId - curId;
if (size(ids) == 1)
{
p[curId] = cost;
if (curId < n - 1)
go(cost - 1);
}
else
{
// xxx..x.x
if (ids.back() > nextId)
{
go(cost / (len + 1));
for (int i : ids)
if (i > nextId)
cost -= p[i];
}
// xxx.....
for (int i = len; i >= 2; i--)
{
int id = curId + i - 1;
if (p[id] == 0)
go(cost / len);
cost -= p[id];
}
p[curId] = cost;
}
}
void buy_souvenirs(int N, long long p0) {
n = N;
bought.assign(n, 0);
p.assign(n, 0);
go(p0 - 1);
for (int i = 1; i < n; i++)
{
assert(bought[i] <= i && p[i] > 0);
while (bought[i] < i)
buy(p[i]);
}
}
