solved https://leetcode-cn.com/problems/single-number/

Author: psc0606

src/array/single-number.go

@@ -0,0 +1,13 @@
+package array
+
+// https://leetcode-cn.com/problems/single-number/
+// Time: O(n)
+// Space: O(1)
+func singleNumber(nums []int) int {
+	// assert at least one elements
+	res := nums[0]
+	for i := 1; i < len(nums); i++ {
+		res ^= nums[i]
+	}
+	return res
+}