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  1. #include <iostream>
  2. #include <bitset>
  3. #include <sstream>
  4.  
  5. using namespace std;
  6.  
  7. unsigned int reverse_bits(unsigned int value) {
  8.   unsigned int result = 0;
  9.   while(value) {
  10.   	result <<= 1;
  11.   	result |= (value & 1);
  12.   	value >>= 1;
  13.   }
  14.   return result;
  15. }
  16.  
  17. template<typename T>
  18. static std::string as_bin(T value) {
  19.   std::stringstream ss;	
  20.   ss << std::bitset<sizeof(T) * 8>(value);
  21.   return ss.str();
  22. }
  23.  
  24. void test(unsigned int input, unsigned int expected_result) {
  25.   unsigned int reversed = reverse_bits(input);
  26.   if (reversed == expected_result) {
  27.   	cout << "Test OK for " << as_bin(input) << " = " << as_bin(reversed) << endl;
  28.   } else {
  29.   	cout << "Test FAIL for " << as_bin(input) << " = " << as_bin(reversed) << endl;
  30.   }
  31. }
  32.  
  33. int main() {
  34. 	cout << "Enter value: ";
  35. 	unsigned int value;
  36. 	cin >> value;
  37. 	unsigned int reversed = reverse_bits(value);
  38. 	cout << "input as bin: " << as_bin(value) << endl;
  39. 	cout << "reversed as bin: " << as_bin(reversed) << endl;
  40. 	test(0b0, 0b0);
  41. 	test(0b1, 0b1);
  42. 	test(0b10, 0b01);
  43. 	test(0b110, 0b011);
  44. 	test(0b11111100, 0b111111);
  45. 	return 0;
  46. }
Success #stdin #stdout 0s 4460KB
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stdout
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Enter value: input as bin: 00000000000000000000000001111011
reversed as bin: 00000000000000000000000001101111
Test OK for 00000000000000000000000000000000 = 00000000000000000000000000000000
Test OK for 00000000000000000000000000000001 = 00000000000000000000000000000001
Test OK for 00000000000000000000000000000010 = 00000000000000000000000000000001
Test OK for 00000000000000000000000000000110 = 00000000000000000000000000000011
Test OK for 00000000000000000000000011111100 = 00000000000000000000000000111111
https://ideone.com/0WOXW5
language:
C++14 (gcc 8.3)
created:
4 years ago
visibility:
public

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