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  1.  
  2. #include <iostream>
  3. #include <vector>
  4.  
  5. void print_vec_pair(std::vector<std::pair<int, int>>& v) {
  6.  
  7. 	for (const auto& a : v) {
  8. 		std::cout << "(" << a.first << ", " << a.second << ") ";
  9. 	}
  10. 	std::cout << std::endl;
  11. }
  12.  
  13. bool compare_pairs(std::pair<int, int>& a, std::pair<int, int>& b) {
  14.  
  15. 	if (a.second == b.second)
  16. 		return true;
  17. 	else
  18. 		return false;
  19. }
  20.  
  21.  
  22. size_t find_seq_len (std::vector<std::pair<int, int>> & data, size_t start, size_t end) {
  23.  
  24. 	size_t len = 0;
  25. 	if (start == end) {
  26. 		return 1;
  27. 	}
  28. 	do {
  29. 		len++;
  30. 	} while (  compare_pairs(data[start], data[start+len])  );
  31.  
  32. 	return len;
  33. }
  34.  
  35. bool is_present(std::vector<std::pair<int, int>>& data, std::pair<int, int>& p) {
  36. 	if (data.back().first == p.first) {
  37. 		return true;
  38. 	}
  39. 	else {
  40. 		return false;
  41. 	}
  42. }
  43.  
  44. std::vector<std::pair<int, int>> decimation(std::vector<std::pair<int, int>>& data, int N) {
  45.  
  46. 	if (N <= 2 || data.size() == 0) {
  47. 		return std::vector<std::pair<int, int>>();
  48. 	}
  49.  
  50. 	std::vector<std::pair<int, int>> res;
  51.  
  52. 	for (size_t i = 0; i < data.size(); ) {
  53.  
  54. 		size_t len = find_seq_len(data, i, data.size() - 1);
  55.  
  56. 		res.push_back(data[i]);
  57. 		for (size_t j = 1; j < len; j++) {
  58. 			if (j % N == 0) {
  59. 				res.push_back(data[i + j - 1]);
  60. 			}
  61. 		}
  62.  
  63. 		if (is_present(res, data[i + len - 1]) == false) {
  64. 			res.push_back(data[i + len - 1]);
  65. 		}
  66.  
  67. 		i+=len;
  68. 	}
  69.  
  70. 	return res;
  71. }
  72.  
  73.  
  74. int main()
  75. {
  76. 	std::vector<std::pair<int, int>> data;
  77. 	data.push_back({ 1, 10 });
  78. 	data.push_back({ 2, 11 });
  79. 	data.push_back({ 3, 11 });
  80. 	data.push_back({ 4, 11 });
  81. 	data.push_back({ 5, 11 });
  82. 	data.push_back({ 6, 10 });
  83. 	data.push_back({ 7, 11 });
  84. 	data.push_back({ 8, 11 });
  85. 	data.push_back({ 9, 11 });
  86. 	data.push_back({ 10, 11 });
  87. 	data.push_back({ 11, 11 });
  88. 	data.push_back({ 12, 11 });
  89. 	data.push_back({ 13, 11 });
  90. 	data.push_back({ 14, 10 });
  91.  
  92. 	auto result3 = decimation(data, 3);
  93. 	auto result4 = decimation(data, 4);
  94.  
  95. 	print_vec_pair(data);
  96. 	std::cout << std::endl;
  97.  
  98. 	print_vec_pair(result3);
  99. 	std::cout << std::endl;
  100.  
  101. 	print_vec_pair(result4);
  102. 	std::cout << std::endl;
  103.  
  104. }
Success #stdin #stdout 0s 4540KB
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Standard input is empty
stdout
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(1, 10) (2, 11) (3, 11) (4, 11) (5, 11) (6, 10) (7, 11) (8, 11) (9, 11) (10, 11) (11, 11) (12, 11) (13, 11) (14, 10) 

(1, 10) (2, 11) (4, 11) (5, 11) (6, 10) (7, 11) (9, 11) (12, 11) (13, 11) (14, 10) 

(1, 10) (2, 11) (5, 11) (6, 10) (7, 11) (10, 11) (13, 11) (14, 10)
https://ideone.com/0Cgled
language:
C++ (gcc 8.3)
created:
4 years ago
visibility:
public

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