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  1. /*
  2.  * List.h
  3.  *
  4.  *  Created on: Dec 12, 2012
  5.  *      Author: MrD
  6.  */
  7.  
  8. #ifndef LIST_H_
  9. #define LIST_H_
  10.  
  11. class List {
  12.     long j;
  13. public:
  14. 	List * next;
  15. 	List * previous;
  16. 	virtual long jj() {
  17. 		return this->j;
  18. 	}
  19. 	List() {
  20. 		next = previous = 0;
  21. 		j = 0; // it still initializes it to 0 - mostly :)
  22. 	}
  23. 	virtual ~List() {
  24. 		if (next) {
  25. 			next->previous = this->previous;
  26. 		}
  27. 		if (previous) {
  28. 			previous->next = this->next;
  29. 		}
  30. 	}
  31. };
  32.  
  33. #endif /* LIST_H_ */
  34.  
  35. #include <time.h>
  36. #include<iostream>
  37. #include <exception>
  38.  
  39. using namespace std;
  40.  
  41. const static int EVERY = 10000;
  42.  
  43. void print(List * begin) {
  44. 	List * biter = begin;
  45. 	while (biter != 0) {
  46. 		cout << biter << " : " << biter->previous << "," << biter->next << endl;
  47. 		biter = biter->next;
  48. 	}
  49. }
  50. void term_func() {
  51. 	cout << "NO USE YOU WON'T SEE ME" << endl;
  52. }
  53. //void handler() {
  54. //	std::cout << "Memory allocation failed, terminating\n";
  55. ////	std::set_new_handler(nullptr);
  56. //}
  57. void deleteNodes(bool slow, List* iter) {
  58. 	iter = iter->next; // do not delete the beginning
  59. 	for (unsigned int var2 = 0; iter; ++var2) {
  60. 		if ((bool) (var2 % EVERY) == slow) {
  61. 			List* temp = iter->next;
  62. 			delete iter;
  63. 			iter = temp;
  64. 		} else
  65. 			iter = iter->next;
  66. 	}
  67. }
  68.  
  69. void traverse(List* iter, List* const BEGIN) {
  70. 	iter = BEGIN;
  71. 	long val = 0;
  72. 	for (List *iter2 = BEGIN; iter2; iter2 = iter2->next) {
  73. 		if (++val > 87910000) {
  74. //			print(iter);
  75. 			cout << val << endl;
  76. 			cout << iter2 << endl;
  77. //			return;
  78. 		}
  79. //		if ((*iter).jj() && (*iter).jj() != val) {
  80. //			val = (*iter).jj();
  81. //			cout << (*iter).jj() << endl;
  82. //		}
  83. 	}
  84. }
  85.  
  86. int main(int argc, char **argv) {
  87. 	cout << "size of List c++ : " << sizeof(List) << endl;
  88. 	set_terminate(term_func);
  89. //	std::set_new_handler(handler);
  90. 	clock_t tStart = clock();
  91. 	List * ptrList = new List();
  92. 	List * const BEGIN = ptrList;
  93. 	unsigned long var = 0;
  94. //	try {
  95. //		while (true) {
  96. //			new int[100000000ul];
  97. //		}
  98. //	} catch (const std::bad_alloc& e) {
  99. //		std::cout << "Allocation failed: " << e.what() << '\n';
  100. //	}
  101. 	try {
  102. 		for (;; ++var) {
  103. //			List * ptrList2 = new List();
  104. 			List * ptrList2 = new (nothrow) List();
  105. 			if (!ptrList2) {
  106. 				cout << "out of memory - created " << var << " nodes" << endl;
  107. 				break;
  108. 			}
  109. 			ptrList->next = ptrList2;
  110. 			ptrList2->previous = ptrList;
  111. 			ptrList = ptrList2;
  112. //			if (!(var % 1000))
  113. //				cout << var << endl;
  114. 		}
  115. 	} catch (bad_alloc const& e) {
  116. 		// there is an exception I can't catch for the life of me
  117. 		// I get it around 87921000 - differing on Eclipse and cmd
  118. 		// Win7 prof x64
  119. 		cout << "caught : " << e.what() << endl;
  120. //	} catch (...) { //this won't work either
  121. 	}
  122. 	//print(BEGIN);
  123. 	if (argc < 2) {
  124. 		List * iter = BEGIN;
  125. 		cout << "Fast delete" << endl;
  126. 		deleteNodes(false, iter);
  127. 		//print(BEGIN);
  128. 		cout << "Fast traverse" << endl;
  129. 		traverse(iter, BEGIN);
  130. 	} else {
  131. 		cout << "slow" << endl;
  132. 		List * iter = BEGIN;
  133. 		cout << "Slow delete" << endl;
  134. 		deleteNodes(true, iter);
  135. 		print(BEGIN);
  136. 		cout << "Slow traverse" << endl;
  137. 		traverse(iter, BEGIN);
  138. 	}
  139. 	cout << "Time taken: " << (double) (clock() - tStart) / CLOCKS_PER_SEC
  140. 			<< endl;
  141.  
  142. 	return 0;
  143. }
  144.  
Success #stdin #stdout 1.37s 262080KB
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stdin
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Standard input is empty
stdout
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size of List c++ : 16
out of memory - created 11066878 nodes
Fast delete
Fast traverse
Time taken: 1.36
https://ideone.com/qBInCR
language:
C++ (gcc 8.3)
created:
11 years ago
visibility:
secret

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