leetcode/c/136.single-number/136.single-number.org

136 Single Number

• Solution

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.

Solution

int xor(int a, int b) {
   return a ^ b;
}

int singleNumber(int* nums, int numsSize) {
    int number = 0;
    for (int i=0; i < numsSize; i++) {
        number = xor(number, nums[i]);
    }
    return number;
}

#include <stdio.h>

<<solution>>

int numbers[3] = {1, 1, 2};
int single = singleNumber(numbers, 3);
printf("%d\n", single);

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