Single Number (XOR)
LeetCode 136 · View on LeetCode
Every element appears twice except one. XOR all elements together. Pairs cancel out (x ^ x = 0), leaving the unique number.
package main
import "fmt"
func singleNumber(nums []int) int {
result := 0
for _, n := range nums {
result ^= n
}
return result
}
func main() {
fmt.Println(singleNumber([]int{2, 2, 1})) // 1
fmt.Println(singleNumber([]int{4, 1, 2, 1, 2})) // 4
fmt.Println(singleNumber([]int{1})) // 1
}