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  1. #include <stdio.h>
  2. #include <memory.h>
  3.  
  4. unsigned getbits(unsigned x, int p, int n);
  5. void printbits(unsigned int x);
  6. unsigned int setbits(unsigned int x, int p, int n, unsigned int y);
  7.  
  8.  
  9. int main(void){
  10. 	unsigned int x = 0;
  11. 	unsigned int y = 198;
  12. 	unsigned int res;
  13.  
  14. 	res = setbits(x, 7, 3, y);
  15. 	printbits(res);
  16.  
  17.  	return 0;
  18. }
  19.  
  20. /*Извлекает n бит начиная с p-й позиции*/
  21. unsigned getbits(unsigned x, int p, int n){
  22. 	return (x >> (p+1-n)) & ~(~0 << n);
  23. }
  24.  
  25. unsigned int setbits(unsigned int x, int p, int n, unsigned int y){
  26. 	unsigned int bit_field;
  27.  
  28. 	printf("%s", "x = ");
  29. 	printbits(x);
  30. 	printf("%s", "y = ");
  31. 	printbits(y);
  32. 	/*Извлечем n крайних правых бит аргумента y*/
  33. 	bit_field = getbits(y, n-1, n);
  34. 	printf("%s", "f = ");
  35. 	printbits(bit_field);
  36. 	printf("%s", "r = ");
  37. 	printbits(bit_field << (p+1-n));
  38. 	return x | (bit_field << (p+1-n));
  39. }
  40.  
  41. void printbits(unsigned int x){
  42. 	int i;
  43. 	int mask = 0x1;
  44.  
  45. 	for(i = 15; i >= 0; i--){
  46. 		printf("%d", (x >> i) & mask);
  47. 		if(!(i % 4)) putchar(' ');
  48. 	}
  49. 	putchar('\n');
  50. }
Success #stdin #stdout 0s 3412KB
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stdin
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Standard input is empty
stdout
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x = 0000 0000 0000 0000 
y = 0000 0000 1100 0110 
f = 0000 0000 0000 0110 
r = 0000 0000 1100 0000 
0000 0000 1100 0000
https://ideone.com/sr5T1z
language:
C++ (gcc 8.3)
created:
8 years ago
visibility:
public

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