#include "tickets.h"
#include <cassert>
#include <vector>
#include <numeric>
#include <algorithm>
#include <functional>
using ll = long long;
struct delta
{
public:
int i, v;
bool operator > (const delta& o) const {return v > o.v;}
};
long long find_maximum(int K, std::vector<std::vector<int>> x) {
int N = x.size();
int M = x[0].size();
std::vector<std::vector<int>> answer(N, std::vector<int>(M, -1));
ll ans=0;
for(int i=0;i<N;++i)
for(int j=0;j<K;++j)
ans -= x[i][j];
std::vector<int> u(N, 0);
std::vector<delta> gains;
for(int i=0;i<N;++i)
for(int j=0;j<K;++j)
gains.push_back({i, x[i][M-j-1]+x[i][K-j-1]});
std::nth_element(gains.begin(), gains.begin()+(N*K/2), gains.end(), std::greater<delta>());
for(int i=0;i<N*K/2;++i)
++u[gains[i].i], ans += gains[i].v; // u = how many R we use
std::vector<int> L(N, 0), R(N, M), ord(N);
std::iota(ord.begin(), ord.end(), 0);
for(int i=0;i<K;++i)
{
std::nth_element(ord.begin(), ord.begin()+N/2, ord.end(), [&](int x, int y){return u[x]<u[y];});
for(int j=0;j<N/2;++j)
answer[ord[j]][L[ord[j]]++]=i;
for(int j=N/2;j<N;++j)
answer[ord[j]][--R[ord[j]]]=i, --u[ord[j]];
}
for(int i=0;i<N;++i)
assert(u[i] == 0);
ll ans2=0;
for(int i=0;i<N;++i)
{
for(int j=0;j<L[i];++j)
ans2 -= x[i][j];
for(int j=R[i];j<M;++j)
ans2 += x[i][j];
}
assert(ans == ans2);
allocate_tickets(answer);
return ans;
}
