190. Reverse Bits LeetCode Solution

In this guide, you will get 190. Reverse Bits LeetCode Solution with the best time and space complexity. The solution to Reverse Bits problem is provided in various programming languages like C++, Java, and Python. This will be helpful for you if you are preparing for placements, hackathons, interviews, or practice purposes. The solutions provided here are very easy to follow and include detailed explanations.

Table of Contents

  1. Problem Statement
  2. Complexity Analysis
  3. Reverse Bits solution in C++
  4. Reverse Bits solution in Java
  5. Reverse Bits solution in Python
  6. Additional Resources
190. Reverse BitsLeetCode Solution image

Problem Statement of Reverse Bits

Reverse bits of a given 32 bits unsigned integer.
Note:

Note that in some languages, such as Java, there is no unsigned integer type. In this case, both input and output will be given as a signed integer type. They should not affect your implementation, as the integer’s internal binary representation is the same, whether it is signed or unsigned.
In Java, the compiler represents the signed integers using 2’s complement notation. Therefore, in Example 2 above, the input represents the signed integer -3 and the output represents the signed integer -1073741825.

Example 1:

Input: n = 00000010100101000001111010011100
Output: 964176192 (00111001011110000010100101000000)
Explanation: The input binary string 00000010100101000001111010011100 represents the unsigned integer 43261596, so return 964176192 which its binary representation is 00111001011110000010100101000000.

Example 2:

Input: n = 11111111111111111111111111111101
Output: 3221225471 (10111111111111111111111111111111)
Explanation: The input binary string 11111111111111111111111111111101 represents the unsigned integer 4294967293, so return 3221225471 which its binary representation is 10111111111111111111111111111111.

Constraints:

The input must be a binary string of length 32

Follow up: If this function is called many times, how would you optimize it?

See also  707. Design Linked List LeetCode Solution

Complexity Analysis

  • Time Complexity: O(32) = O(1)
  • Space Complexity: O(1)

190. Reverse Bits LeetCode Solution in C++

class Solution {
 public:
  uint32_t reverseBits(uint32_t n) {
    uint32_t ans = 0;

    for (int i = 0; i < 32; ++i)
      if (n >> i & 1)
        ans |= 1 << 31 - i;

    return ans;
  }
};
/* code provided by PROGIEZ */

190. Reverse Bits LeetCode Solution in Java

class Solution {
  // You need treat n as an unsigned value
  public int reverseBits(int n) {
    int ans = 0;

    for (int i = 0; i < 32; ++i)
      if ((n >> i & 1) == 1)
        ans |= 1 << 31 - i;

    return ans;
  }
}
// code provided by PROGIEZ

190. Reverse Bits LeetCode Solution in Python

class Solution:
  def reverseBits(self, n: int) -> int:
    ans = 0

    for i in range(32):
      if n >> i & 1:
        ans |= 1 << 31 - i

    return ans
 # code by PROGIEZ

Additional Resources

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