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Oct 16th, 2018
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  1. #include <iostream>
  2. #include <vector>
  3. #include <utility>
  4. #include <cmath>
  5.  
  6. double edge_weight(std::pair<int, int> a, std::pair<int, int> b) {
  7. return std::sqrt(std::pow(a.first - b.first, 2) + std::pow(a.second - b.second, 2));
  8. }
  9.  
  10. double kruskal(int ver_num, std::vector<std::pair<double, std::pair<int, int>>>& edges) {
  11. size_t edge_num = edges.size();
  12. std::sort(std::begin(edges), std::end(edges));
  13. std::vector<int> treeId(ver_num);
  14. for (int32_t i = 0; i < ver_num; i++) {
  15. treeId[i] = i;
  16. }
  17. double mstCost = 0;
  18. std::vector<std::pair<int, std::pair<int, int>>> edgesInMST;
  19. for (int i = 0; i < edge_num; i++) {
  20. int firstVer = edges[i].second.first, secVer = edges[i].second.second;
  21. double cost = edges[i].first;
  22. if (treeId[firstVer] != treeId[secVer]) {
  23. edgesInMST.emplace_back(std::make_pair(cost, std::make_pair(firstVer, secVer)));
  24. mstCost += cost;
  25. int oldTree = treeId[firstVer];
  26. for (int j = 0; j < ver_num; ++j) {
  27. if (treeId[j] == oldTree)
  28. treeId[j] = treeId[secVer];
  29. }
  30. }
  31. }
  32. return mstCost;
  33. }
  34.  
  35. int main() {
  36. int num_terminal, num_extra;
  37. std::cin >> num_terminal >> num_extra;
  38. std::vector<std::pair<int, int> > vertices(num_terminal);
  39. std::vector<std::pair<int, int> > added_vertices;
  40. std::vector<std::pair<double, std::pair<int, int> > > edges;
  41. for (int i = 0; i != num_terminal; ++i) {
  42. std::cin >> vertices[i].first >> vertices[i].second;
  43. }
  44. int right = -1;
  45. int down = 100000;
  46. int up = -1;
  47. int left = 100000;
  48. for (int j = 0; j != num_terminal; ++j) {
  49. if (right < vertices[j].first) {
  50. right = vertices[j].first;
  51. }
  52. if (down > vertices[j].second) {
  53. down = vertices[j].second;
  54. }
  55. if (up < vertices[j].second) {
  56. up = vertices[j].second;
  57. }
  58. if (left > vertices[j].first) {
  59. left = vertices[j].first;
  60. }
  61. }
  62. std::cout << "OKI\n";
  63. for (int i = 0; i != num_terminal; ++i) {
  64. for (int j = i + 1; j < num_terminal; ++j) {
  65. edges.emplace_back(std::make_pair(edge_weight(vertices[i], vertices[j]), std::make_pair(i, j)));
  66. }
  67. }
  68. double best_mst = kruskal(num_terminal, edges);
  69. std::cout << best_mst << "\n";
  70. int new_num_vert = num_terminal;
  71. int step1 = 1;
  72. int step2 = 1;
  73. if (right - left >= 1000) {
  74. step1 = (right - left) / 300;
  75. }
  76. if (up - down >= 1000) {
  77. step2 = (up - down) / 400;
  78. }
  79. std::cout << right << "\n";
  80. for (int i = down; i < up; i += step1) {
  81. for (int j = left; j < right && num_extra != 0; j += step2) {
  82. std::vector<std::pair<double, std::pair<int, int> > > copy_edges = edges;
  83. std::pair<int, int> possible_vert = std::make_pair(i, j);
  84. for(int k = 0; k != new_num_vert; ++k) {
  85. copy_edges.push_back(std::make_pair(edge_weight(possible_vert, vertices[k]), std::make_pair(k, new_num_vert)));
  86. }
  87. double loc_mst = kruskal(new_num_vert + 1, copy_edges);
  88. if (j == 9 && i == 1) {
  89. std::cout << loc_mst << "\n";
  90. }
  91. if (loc_mst < best_mst) {
  92. best_mst = loc_mst;
  93. edges = copy_edges;
  94. --num_extra;
  95. ++new_num_vert;
  96. vertices.push_back(possible_vert);
  97. added_vertices.push_back(possible_vert);
  98. }
  99. }
  100. }
  101. std::cout << added_vertices.size() << "\n";
  102. for (auto x : added_vertices) {
  103. std::cout << x.first << " " << x.second << "\n";
  104. }
  105. return 0;
  106. }
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