merge_sorted_array_88: additional solution

Author: austingebauer

go.sum

@@ -1,11 +1,11 @@
-github.com/austingebauer/leetcode v0.0.0-20200305172347-4c676793876f h1:A/S3S1hRavbbUCRkWer4VGKpMhavNVroN1on5YFUH2I=
 github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.5.1 h1:nOGnQDM7FYENwehXlg/kFVnos3rEvtKTjRvOWSzb6H4=
 github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=

merge_sorted_array_88/solution.go

@@ -1,5 +1,24 @@
 package merge_sorted_array_88
 
+// O(m+n) solution
+func merge(nums1 []int, m int, nums2 []int, n int) {
+	if n == 0 {
+		return
+	}
+
+	n1, n2, p := m-1, n-1, m+n-1
+	for n2 > -1 {
+		if n1 < 0 || nums2[n2] >= nums1[n1] {
+			nums1[p] = nums2[n2]
+			n2--
+		} else {
+			nums1[p] = nums1[n1]
+			n1--
+		}
+		p--
+	}
+}
+
 // Note: solution from rotate_string_796 interview that stumped me for a bit.
 // Wanted to solve without shifting and was tricky.
 func merge2(nums1 []int, m int, nums2 []int, n int) {
@@ -34,7 +53,7 @@ func merge2(nums1 []int, m int, nums2 []int, n int) {
 }
 
 // Note: original solution with array shifting
-func merge(nums1 []int, m int, nums2 []int, n int) {
+func merge0(nums1 []int, m int, nums2 []int, n int) {
 	slot := 0
 
 	// for each in nums2, insert into nums1

merge_sorted_array_88/solution_test.go

@@ -1,8 +1,9 @@
 package merge_sorted_array_88
 
 import (
-	"github.com/stretchr/testify/assert"
 	"testing"
+
+	"github.com/stretchr/testify/assert"
 )
 
 func Test_merge(t *testing.T) {
@@ -68,7 +69,7 @@ func Test_merge(t *testing.T) {
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			// merge2(tt.args.nums1, tt.args.m, tt.args.nums2, tt.args.n)
+			//merge0(tt.args.nums1, tt.args.m, tt.args.nums2, tt.args.n)
 			merge(tt.args.nums1, tt.args.m, tt.args.nums2, tt.args.n)
 			assert.Equal(t, tt.want, tt.args.nums1)
 		})