268. Missing Number

Author: maxvoronov

README.md

@@ -1,6 +1,6 @@
 # LeetCode
 
-![Problems Solved](https://img.shields.io/badge/Problems%20Solved-21%20%2F%202077-1f425f?logo=leetcode) 
+![Problems Solved](https://img.shields.io/badge/Problems%20Solved-23%20%2F%202077-1f425f?logo=leetcode) 
 ![Language: Golang](https://img.shields.io/badge/language-Golang-00ADD8?logo=go) 
 ![Language: Rust](https://img.shields.io/badge/language-Rust-00ADD8?logo=rust) 
 ![Language: Bash](https://img.shields.io/badge/language-Bash-00ADD8?logo=gnubash&logoColor=f5f5f5) 
@@ -24,6 +24,7 @@
 | 136 | [Single Number](https://leetcode.com/problems/single-number/)                                                                   | [Go](go/0136_single_number)                                                     |     🟢     |      Array, Bit Manipulation       |
 | 155 | [Min Stack](https://leetcode.com/problems/min-stack/)                                                                           | [Go](go/0155_min_stack)                                                         |     🟢     |               Stack                |
 | 226 | [Invert Binary Tree](https://leetcode.com/problems/invert-binary-tree/)                                                         | [Go](go/0226_invert_binary_tree)                                                |     🟢     |    Tree, BFS, DFS, Binary Tree     |
+| 268 | [Missing Number](https://leetcode.com/problems/missing-number/)                                                                 | [Go](go/0268_missing_number)                                                    |     🟢     |   Array, Math, Bit Manipulation    |
 | 283 | [Move Zeroes](https://leetcode.com/problems/move-zeroes/)                                                                       | [Go](go/0283_move_zeroes)                                                       |     🟢     |           Array, Pointer           |
 | 344 | [Reverse String](https://leetcode.com/problems/reverse-string/)                                                                 | [Go](go/0344_reverse_string), [Rust](rust/_0344_reverse_string)                 |     🟢     |          String, Pointer           |
 | 404 | [Sum of Left Leaves](https://leetcode.com/problems/sum-of-left-leaves/)                                                         | [Go](go/0404_sum_of_left_leaves)                                                |     🟢     |    Tree, BFS, DFS, Binary Tree     |

go/0268_missing_number/solution.go

@@ -0,0 +1,13 @@
+package missing_number
+
+func missingNumber(nums []int) (result int) {
+	for i := 0; i <= len(nums); i++ {
+		result ^= i
+	}
+
+	for _, num := range nums {
+		result ^= num
+	}
+
+	return
+}

go/0268_missing_number/solution_test.go

@@ -0,0 +1,22 @@
+package missing_number
+
+import "testing"
+
+func Test_singleNumber(t *testing.T) {
+	tests := []struct {
+		input []int
+		want  int
+	}{
+		{input: []int{3, 0, 1}, want: 2},
+		{input: []int{0, 1}, want: 2},
+		{input: []int{9, 6, 4, 2, 3, 5, 7, 0, 1}, want: 8},
+		{input: []int{1}, want: 0},
+	}
+
+	for i, tc := range tests {
+		got := missingNumber(tc.input)
+		if tc.want != got {
+			t.Fatalf("Case #%d: expected: %v, got: %v", i+1, tc.want, got)
+		}
+	}
+}