Add: rotate_image

Author: Openset

problems/rotate-image/rotate_image.go

@@ -1 +1,15 @@
 package rotate_image
+
+func rotate(matrix [][]int) {
+	l := len(matrix)
+	t := make([][]int, l)
+	for i := 0; i < l; i++ {
+		t[i] = make([]int, l)
+		copy(t[i], matrix[i])
+	}
+	for i := 0; i < l; i++ {
+		for j := 0; j < l; j++ {
+			matrix[j][l-1-i] = t[i][j]
+		}
+	}
+}

problems/rotate-image/rotate_image_test.go

@@ -1 +1,55 @@
 package rotate_image
+
+import (
+	"reflect"
+	"testing"
+)
+
+type caseType struct {
+	input    [][]int
+	expected [][]int
+}
+
+func TestRotate(t *testing.T) {
+	tests := [...]caseType{
+		{
+			input: [][]int{
+				{1, 2, 3},
+				{4, 5, 6},
+				{7, 8, 9},
+			},
+			expected: [][]int{
+				{7, 4, 1},
+				{8, 5, 2},
+				{9, 6, 3},
+			},
+		},
+		{
+			input: [][]int{
+				{5, 1, 9, 11},
+				{2, 4, 8, 10},
+				{13, 3, 6, 7},
+				{15, 14, 12, 16},
+			},
+			expected: [][]int{
+				{15, 13, 2, 5},
+				{14, 3, 4, 1},
+				{12, 6, 8, 9},
+				{16, 7, 10, 11},
+			},
+		},
+	}
+
+	for _, tc := range tests {
+		l := len(tc.input)
+		output := make([][]int, l)
+		for i := 0; i < l; i++ {
+			output[i] = make([]int, l)
+			copy(output[i], tc.input[i])
+		}
+		rotate(output)
+		if !reflect.DeepEqual(output, tc.expected) {
+			t.Fatalf("input: %v, output: %v, expected: %v", tc.input, output, tc.expected)
+		}
+	}
+}