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Reverse Bits of an Integer

Certification: Basic Level Accuracy: 0% Submissions: 0 Points: 5

Write a C program to reverse the bits of a given 32-bit unsigned integer. The program should return the integer obtained after reversing the bits.

Example 1
    
  
  • Input: n = 43261596 (represented in binary as 00000010100101000001111010011100)
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  • Output: 964176192 (represented in binary as 00111001011110000010100101000000)
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  • Explanation: The binary representation of 43261596 is 00000010100101000001111010011100. 
    Reversing all bits gives 00111001011110000010100101000000. 
    The decimal value of 00111001011110000010100101000000 is 964176192.
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Example 2
    
  
  • Input: n = 4294967293 (represented in binary as 11111111111111111111111111111101)
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  • Output: 3221225471 (represented in binary as 10111111111111111111111111111111)
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  • Explanation: The binary representation of 4294967293 is 11111111111111111111111111111101. 
    Reversing all bits gives 10111111111111111111111111111111. 
    The decimal value of 10111111111111111111111111111111 is 3221225471.
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Constraints
    
  
  • The input must be a 32-bit unsigned integer.
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  • You need to handle the entire 32-bit number, even leading zeros.
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  • Time Complexity: O(1) - because we're dealing with a fixed-size integer (32 bits).
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  • Space Complexity: O(1) - only using a constant amount of extra space.
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Hint
Solution

Solution Hints

    
  
  • Initialize a result variable to 0.
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  • Iterate through all 32 bits of the input integer.
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  • For each bit position, check if the corresponding bit in the input is set (1).
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  • If the bit is set, set the corresponding bit in the reversed position of the result.
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  • Return the final result after processing all 32 bits.
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  • Be careful about bit shifting operations and data types.
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  • Consider using bitwise operations like left shift (<<), right shift (>>), and bitwise AND (&).
    •

Steps to solve by this approach:

 Step 1: Initialize a result variable to 0 to store our reversed number.

 Step 2: Loop through all 32 bits of the input number.

 Step 3: For each iteration, left shift the result by 1 to make room for the next bit.

 Step 4: Check if the least significant bit of n is 1 using bitwise AND operation (n & 1).

 Step 5: If it's 1, set the least significant bit of result to 1 using bitwise OR operation (result |= 1).

 Step 6: Right shift n by 1 to process the next bit.

 Step 7: After 32 iterations, return the final result.

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