Package g0101_0200.s0136_single_number

Class Solution

java.lang.Object
g0101_0200.s0136_single_number.Solution
public class Solution extends Object
136 - Single Number.

Easy

Given a non-empty array of integers nums, every element appears twice except for one. Find that single one.

You must implement a solution with a linear runtime complexity and use only constant extra space.

Example 1:

Input: nums = [2,2,1]

Output: 1

Example 2:

Input: nums = [4,1,2,1,2]

Output: 4

Example 3:

Input: nums = [1]

Output: 1

Constraints:

  • 1 <= nums.length <= 3 * 104
  • -3 * 104 <= nums[i] <= 3 * 104
  • Each element in the array appears twice except for one element which appears only once.

To solve the “Single Number” problem in Java with a Solution class, we’ll use bitwise XOR operation. Below are the steps:

  1. Create a Solution class: Define a class named Solution to encapsulate our solution methods.

  2. Create a singleNumber method: This method takes an array nums as input and returns the single number that appears only once.

  3. Initialize a variable to store the result: Initialize a variable singleNumber to 0.

  4. Iterate through the array and perform bitwise XOR operation: Iterate through the array nums. For each number num in the array, perform bitwise XOR operation with the singleNumber.

  5. Return the result: After iterating through the entire array, the singleNumber variable will store the single number that appears only once. Return singleNumber.

Here’s the Java implementation:

class Solution {
    public int singleNumber(int[] nums) {
        int singleNumber = 0; // Initialize variable to store result
        
        // Perform bitwise XOR operation on all elements in the array
        for (int num : nums) {
            singleNumber ^= num;
        }
        
        return singleNumber; // Return the single number
    }
}

This implementation follows the steps outlined above and efficiently finds the single number that appears only once in the given array using bitwise XOR operation in Java.

  • Constructor Details

    • Solution

      public Solution()

  • Method Details

    • singleNumber

      public int singleNumber(int[] nums)