school/semester_5/aturp/naloga_4/main.cpp

#include <iostream>
#include <fstream>
#include <vector>
#include <array>

struct island
{
  int L;
  int R;
  int time;
};
#define LEFT 0
#define FROM_LEFT 1
#define ACROSS 2
#define RIGHT 3
#define FROM_RIGHT 4
#define MAX_NUM 10000000

std::vector<std::array<int, 5>> get_line_combinations(std::vector<island> &line)
{

  std::vector<std::array<int, 5>> comp(line.size(), std::array<int, 5>({0}));
  if (line.size() == 0)
  {
    return comp;
  }
  // going across the line
  std::sort(line.begin(), line.end(), [](const island &a, const island &b)
            { return a.time < b.time; });
  for (size_t i = 0; i < line.size(); i++)
  {
    if (i == 0)
    {
      comp[i][ACROSS] = line[i].time + line[i].L + line[i].R;
    }
    else
    {
      comp[i][ACROSS] = comp[i - 1][ACROSS] + line[i].time;
    }
  }

  // going back

  std::sort(line.begin(), line.end(), [](const island &a, const island &b)
            { return a.L < b.L; });

  std::vector<bool> Lused(line.size(), false);
  int most_right_island = 0;
  int Lmin = MAX_NUM;
  int Lval = 0;
  int dist = 0;
  int Lindex = 0;
  int FLmin = 0;

  std::vector<bool> Rused(line.size(), false);
  int most_left_island = line.size();
  int Rmin = MAX_NUM;
  int Rval = 0;
  int Rindex = 0;
  int FRmin = 0;

  int tmp = 0;
  for (size_t i = 0; i < line.size(); i++)
  {
    if (i == 0)
    {
      for (size_t j = 0; j < line.size(); j++)
      {
        Lval = line[j].L + line[j].L + line[j].time;
        if (Lval < Lmin)
        {
          Lmin = Lval;
          Lindex = j;
          FLmin = line[j].L + line[j].time;
        }

        Rval = line[j].R + line[j].R + line[j].time;
        if (Rval < Rmin)
        {
          Rmin = Rval;
          Rindex = j;
          FRmin = line[j].R + line[j].time;
        }
      }
    }
    else
    {
      for (size_t j = 0; j < line.size(); j++)
      {
        if (!Lused[j])
        {
          if (j < most_right_island)
          {
            Lval = comp[i - 1][LEFT] + line[j].time;
            tmp = comp[i - 1][FROM_LEFT] + line[j].time;
          }
          else
          {
            dist = line[j].L - line[most_right_island].L;
            Lval = comp[i - 1][LEFT] + dist + dist + line[j].time;
            tmp = comp[i - 1][FROM_LEFT] + dist + line[j].time;
          }
          if (Lval < Lmin)
          {
            Lindex = j;
            Lmin = Lval;
            FLmin = tmp;
          }
        }
        if (!Rused[j])
        {

          if (j > most_left_island)
          {
            Rval = comp[i - 1][RIGHT] + line[j].time;
            tmp = comp[i - 1][FROM_RIGHT] + line[j].time;
          }
          else
          {
            dist = line[j].R - line[most_left_island].R;
            Rval = comp[i - 1][RIGHT] + dist + dist + line[j].time;
            tmp = comp[i - 1][FROM_RIGHT] + dist + line[j].time;
          }

          if (Rval < Rmin)
          {
            Rindex = j;
            Rmin = Rval;
            FRmin = tmp;
          }
        }
      }
    }

    if (Rindex < most_left_island)
    {
      most_left_island = Rindex;
    }
    Rused[Rindex] = true;
    comp[i][RIGHT] = Rmin;
    Rmin = MAX_NUM;
    comp[i][FROM_RIGHT] = FRmin;

    if (Lindex > most_right_island)
    {
      most_right_island = Lindex;
    }
    Lused[Lindex] = true;
    comp[i][LEFT] = Lmin;
    Lmin = MAX_NUM;
    comp[i][FROM_LEFT] = FLmin;
  }

  return comp;
}

void print_deb(std::vector<int> &RESULT, std::vector<std::array<int, 2>> &A)
{
  for (size_t i = 0; i < RESULT.size(); i++)
  {
    std::cout << RESULT[i] << " ";
  }

  std::cout << std::endl
            << std::endl;

  for (size_t i = 0; i < A.size(); i++)
  {
    std::cout << A[i][0] << " " << A[i][1] << std::endl;
  }
  std::cout << std::endl;
}

void increse(std::vector<std::array<int, 2>> &A)
{
  for (size_t i = 0; i < A.size(); i++)
  {
    A[i][0]++;
    A[i][1]++;
  }
}

void print_line(std::vector<island> &line)
{
  for (size_t i = 0; i < line.size(); i++)
  {
    std::cout << line[i].L << " " << line[i].time << " " << line[i].R << std::endl;
  }
  std::cout << std::endl;
}

void print_comp(std::vector<std::array<int, 5>> &comp)
{
  for (size_t i = 0; i < comp.size(); i++)
  {
    std::cout << comp[i][LEFT] << " " << comp[i][FROM_LEFT] << " " << comp[i][ACROSS] << " " << comp[i][RIGHT] << " " << comp[i][FROM_RIGHT] << std::endl;
  }
  std::cout << std::endl;
}

int main(int argc, char *argv[])
{
  std::ifstream in(argv[1]);
  if (!in)
  {
    std::cout << "Cannot open file.\n";
    return 1;
  }

  // N = visina
  int N;
  // sirina
  int M;
  // stevilo otokov
  int K;
  in >> N >> M >> K;
  M--;

  std::vector<std::vector<island>> map(N, std::vector<island>());
  int x, y, t;
  for (size_t i = 0; i < K; i++)
  {

    in >> x >> y >> t;
    x--;
    y--;
    map[x].emplace_back(island{y, M - y, t});
  }
  in.close();

  std::vector<int> RESULT(K + 1, MAX_NUM);
  std::vector<std::array<int, 2>> A(K + 1, {MAX_NUM, MAX_NUM});
  RESULT[0] = 0;
  A[0][0] = 0;
  A[0][1] = M;
  std::vector<std::array<int, 2>> B = A;

  int num_of_islands = 0;

  std::vector<std::array<int, 5>> comp = get_line_combinations(map[0]);

  num_of_islands = comp.size();

  for (size_t i = 0; i < comp.size(); i++)
  {
    RESULT[i + 1] = std::min(RESULT[i + 1], comp[i][FROM_LEFT]);
    B[i + 1][0] = std::min(A[i + 1][0], comp[i][LEFT]);
    B[i + 1][1] = std::min(A[i + 1][1], comp[i][ACROSS]);
  }
  increse(B);
  A = B;

  int prev = 0;
  int tmp_left = 0;
  int tmp_right = 0;
  int tmp2, tmp3;
  for (size_t i = 1; i < map.size(); i++)
  {
    comp = get_line_combinations(map[i]);
    num_of_islands += comp.size();
    for (size_t j = 1; j <= num_of_islands && comp.size() > 0; j++)
    {
      tmp_left = MAX_NUM;
      tmp_right = MAX_NUM;
      for (size_t k = 0; k < j && k < comp.size(); k++)
      {
        prev = j - (k + 1);
        RESULT[j] = std::min({RESULT[j], A[prev][0] + comp[k][FROM_LEFT], A[prev][1] + comp[k][FROM_RIGHT]});

        tmp2 = std::min({A[j][0], A[prev][0] + comp[k][LEFT], A[prev][1] + comp[k][ACROSS]});
        if (tmp2 < tmp_left)
        {
          tmp_left = tmp2;
        }
        tmp3 = std::min({A[j][1], A[prev][0] + comp[k][ACROSS], A[prev][1] + comp[k][RIGHT]});
        if (tmp3 < tmp_right)
        {
          tmp_right = tmp3;
        }
      }
      B[j][0] = tmp_left;
      B[j][1] = tmp_right;
    }
    increse(B);
    A = B;
  }

  for (size_t i = 1; i < RESULT.size(); i++)
  {
    std::cout << RESULT[i] << " ";
  }

  std::cout << std::endl;
  return 0;
}