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  1. #include <stdio.h>
  2. 	#include <stdlib.h>
  3. 	#include <stdbool.h>
  4. 	#include <string.h>
  5.  
  6. 	struct IP
  7. 	{
  8. 		char ip[20];
  9. 		int cidr;
  10. 		unsigned long mask;
  11. 		unsigned long binary;
  12. 	};
  13. 	void ip_init(struct IP *ip, const char *format);
  14. 	unsigned long ip_to_long(const int ip[4]);
  15. 	int ip_sort_by_format(const void *e1, const void *e2);
  16. 	int ip_sort_by_cidr(const void *e1, const void *e2);
  17. 	void strip(char *input);
  18. 	int main(void)
  19. 	{
  20. 		int N;
  21. 		scanf("%d\n", &N);
  22. 		struct IP ips[N];
  23. 		int cur = 0;
  24. 		for(int i = 0; i < N; i++)
  25. 		{
  26. 			char line[20];
  27. 			fgets(line, 20, stdin);
  28. 			strip(line);
  29. 			ip_init(&ips[cur], line);
  30. 			cur++;
  31. 		}
  32.  
  33. 		qsort(ips, cur, sizeof(struct IP), ip_sort_by_format);
  34. 		for(int i = 0; i < cur; i++)
  35. 		{
  36. 			for(int j = 0; j < cur; j++)
  37. 			{
  38. 				if(i == j)
  39. 					continue;
  40. 				if(strcmp(ips[i].ip, "_") == 0)
  41. 					continue;
  42. 				if(strcmp(ips[j].ip, "_") == 0)
  43. 					continue;
  44.  
  45. 				int small = ips[i].cidr < ips[j].cidr ? i : j;
  46. 				unsigned long masks[2] = {
  47. 					ips[i].binary & ips[small].mask,
  48. 					ips[j].binary & ips[small].mask
  49. 				};
  50.  
  51. 				if(masks[0] == masks[1])
  52. 					strcpy(ips[j].ip, "_");
  53. 			}
  54. 		}
  55.  
  56. 		qsort(ips, cur, sizeof(struct IP), ip_sort_by_cidr);
  57. 		for(int i = 0; i < cur; i++)
  58. 			if(strcmp(ips[i].ip, "_") != 0)
  59. 				printf("%s\n", ips[i].ip);
  60. 		printf("\n");
  61.  
  62. 		return 0;
  63. 	}
  64.  
  65. 	void ip_init(struct IP *ip, const char *format)
  66. 	{
  67. 		int parts[4];
  68. 		int cidr;
  69. 		sscanf(format, "%d.%d.%d.%d/%d", &parts[0], &parts[1], &parts[2], &parts[3], &cidr);
  70.  
  71. 		ip->cidr = cidr;
  72. 		ip->binary = ip_to_long(parts);
  73. 		ip->mask = ~(1 << (cidr + 1)) << (32 - cidr);
  74. 		strcpy(ip->ip, format);
  75. 	}
  76.  
  77. 	unsigned long ip_to_long(const int ip[4])
  78. 	{
  79. 		return ip[3] | ip[2] << 8 | ip[1] << 16 | ip[0] << 24;
  80. 	}
  81.  
  82. 	void strip(char *input)
  83. 	{
  84. 		char *eol = strrchr(input, '\n');
  85. 		if(eol != NULL)
  86. 			*eol = '\0';
  87. 	}
  88.  
  89. 	int ip_sort_by_format(const void *e1, const void *e2)
  90. 	{
  91. 		struct IP *ip1 = (struct IP *) e1;
  92. 		struct IP *ip2 = (struct IP *) e2;
  93.  
  94. 		int diff = (ip1->binary & ip1->mask) - (ip2->binary & ip2->mask);
  95. 		if(diff == 0)
  96. 			return ip1->cidr < ip2->cidr;
  97. 		return diff;
  98. 	}
  99.  
  100. 	int ip_sort_by_cidr(const void *e1, const void *e2)
  101. 	{
  102. 		struct IP *ip1 = (struct IP *) e1;
  103. 		struct IP *ip2 = (struct IP *) e2;
  104. 		return ip1->cidr - ip2->cidr;
  105. 	}
Success #stdin #stdout 0s 9432KB
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stdin
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13
	192.168.0.0/16
	172.24.96.17/32
	172.50.137.225/32
	202.139.219.192/32
	172.24.68.0/24
	192.183.125.71/32
	201.45.111.138/32
	192.168.59.211/32
	192.168.26.13/32
	172.24.0.0/17
	172.24.5.1/32
	172.24.68.37/32
	172.24.168.32/32
stdout
copy 
192.168.0.0/16
	172.24.0.0/17
	172.50.137.225/32
	192.183.125.71/32
	201.45.111.138/32
	202.139.219.192/32
https://ideone.com/n5eBIe
language:
C (gcc 8.3)
created:
7 years ago
visibility:
public

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