plusOne

plusOne/plusOne.go

@@ -0,0 +1,18 @@
+package main
+
+func plusOne(digits []int) []int {
+	lastI := len(digits) - 1
+	digits[lastI] += 1
+	currentI := lastI
+	for currentI >= 0 && digits[currentI] > 9 {
+		digits[currentI] = 0
+		currentI--
+		if currentI >= 0 {
+			digits[currentI]++
+		}
+	}
+	if digits[0] == 0 {
+		digits = append([]int{1}, digits...)
+	}
+	return digits
+}

plusOne/plusOne_test.go

@@ -0,0 +1,64 @@
+package main
+
+import (
+	"reflect"
+	"testing"
+)
+
+// Example 1:
+
+// Input: digits = [1,2,3]
+// Output: [1,2,4]
+// Explanation: The array represents the integer 123.
+// Incrementing by one gives 123 + 1 = 124.
+// Thus, the result should be [1,2,4].
+// Example 2:
+
+// Input: digits = [4,3,2,1]
+// Output: [4,3,2,2]
+// Explanation: The array represents the integer 4321.
+// Incrementing by one gives 4321 + 1 = 4322.
+// Thus, the result should be [4,3,2,2].
+// Example 3:
+
+// Input: digits = [9]
+// Output: [1,0]
+// Explanation: The array represents the integer 9.
+// Incrementing by one gives 9 + 1 = 10.
+// Thus, the result should be [1,0].
+
+func TestPlusOne(t *testing.T) {
+	t.Run("1, 2, 3", func(t *testing.T) {
+
+		digits := []int{1, 2, 3}
+		want := []int{1, 2, 4}
+
+		got := plusOne(digits)
+
+		if !reflect.DeepEqual(got, want) {
+			t.Errorf("got %v, want %v", got, want)
+		}
+	})
+	t.Run("4,3,2,1", func(t *testing.T) {
+
+		digits := []int{4, 3, 2, 1}
+		want := []int{4, 3, 2, 2}
+
+		got := plusOne(digits)
+
+		if !reflect.DeepEqual(got, want) {
+			t.Errorf("got %v, want %v", got, want)
+		}
+	})
+	t.Run("4,3,2,1", func(t *testing.T) {
+
+		digits := []int{9}
+		want := []int{1, 0}
+
+		got := plusOne(digits)
+
+		if !reflect.DeepEqual(got, want) {
+			t.Errorf("got %v, want %v", got, want)
+		}
+	})
+}