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  1. #include <stdio.h>
  2. #include <stdlib.h>
  3. #include <time.h>
  4. #include <memory.h>
  5.  
  6. #define bit(_x_) (1U << (_x_))
  7.  
  8. void randomfillarray( unsigned int * arr, size_t size ) {
  9. 	srand( time( NULL ) );
  10. 	for ( int i = 0; i < size; i++ )
  11. 		arr[i] = rand( );
  12. }
  13.  
  14. int main( ) {
  15. 	unsigned int arr[10];
  16. 	size_t size = sizeof arr / sizeof * arr;
  17. 	randomfillarray( arr, size );
  18.  
  19. 	unsigned int * resultantcouple = malloc( sizeof arr );
  20. 	memcpy( resultantcouple, arr, sizeof arr );
  21.  
  22. 	for ( int i = 0; i < size; i++ )
  23. 		printf( i ? " %u" : "%u", arr[i] );
  24. 	putchar( '\n' );
  25.  
  26. 	int success = 0;
  27.  
  28. 	for ( unsigned int thebit = bit( sizeof( int ) * 8 - 1 ); thebit; thebit >>= 1 ) {
  29. 		int count = 0;
  30. 		int * indices = NULL;
  31. 		for ( int i = 0; i < size; i++ ) {
  32. 			if ( resultantcouple[i] & thebit ) {
  33. 				indices = realloc( indices, ++count * sizeof * indices );
  34. 				indices[count - 1] = i;
  35. 			}
  36. 		}
  37. 		if ( count >= 2 ) {
  38. 			size = count;
  39. 			for ( int i = 0; i < size; i++ )
  40. 				resultantcouple[i] = resultantcouple[indices[i]];
  41. 			resultantcouple = realloc( resultantcouple, size * sizeof * resultantcouple );
  42. 		}
  43. 		if ( size == 2 ) {
  44. 			success = 1;
  45. 			break;
  46. 		}
  47. 		free( indices );
  48. 	}
  49.  
  50. 	if ( success )
  51. 		printf( "Success! %u and %u are the ones.", resultantcouple[0], resultantcouple[1] );
  52. 	else
  53. 		printf( "Failure! Either all pairs are bitwise distinct, or there are less than 2 elements, or something else..." );
  54.  
  55.  
  56. 	putchar( '\n' );
  57. 	return 0;
  58. }
Success #stdin #stdout 0s 2380KB
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stdin
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stdout
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112681642 1998444988 1020495738 1770693426 913084976 932014602 1144788178 95777753 1845835807 75638767
Success! 1770693426 and 1845835807 are the ones.
https://ideone.com/hRA8tn
language:
C99 (gcc 8.3)
created:
11 years ago
visibility:
public

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