ShellSort

README.md

@@ -1,2 +1,5 @@
 # Datastructures & Utility functions for GoLang 
-A basic GoLang module providing some datastructure implementations and utility functions for GoLang.
+A basic GoLang module providing some datastructure implementations and utility functions for GoLang.
+
+## Resources
+https://www.tutorialspoint.com/data_structures_algorithms/index.htm

slice_sorting/shell_sort/shell_sort.go

@@ -0,0 +1,28 @@
+package shellsort
+
+func ShellSort(slice []int) {
+	interval := 1
+	inner := 0
+	outer := 0
+	insertValue := 0
+
+	for interval <= len(slice)/3 {
+		interval = interval*3 + 1
+	}
+
+	for interval > 0 {
+		for outer = interval; outer < len(slice); outer++ {
+			insertValue = slice[outer]
+			inner = outer
+
+			for inner > interval-1 && slice[inner-interval] >= insertValue {
+				slice[inner] = slice[inner-interval]
+				inner = inner - interval
+			}
+
+			slice[inner] = insertValue
+		}
+		interval = (interval - 1) / 3
+	}
+
+}

slice_sorting/shell_sort/shell_sort_test.go

@@ -0,0 +1,33 @@
+package shellsort
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestShellSort(t *testing.T) {
+	type args struct {
+		slice []int
+	}
+	tests := []struct {
+		name string
+		args args
+		want []int
+	}{
+		{
+			name: "it sorts the slice correctly",
+			args: args{
+				slice: []int{6, 1, 8, 9},
+			},
+			want: []int{1, 6, 8, 9},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			ShellSort(tt.args.slice)
+			if !reflect.DeepEqual(tt.want, tt.args.slice) {
+				t.Errorf("the sort failed, want: %v, got: %v", tt.want, tt.args.slice)
+			}
+		})
+	}
+}