Add: K Closest Points to Origin

Author: openset

problems/k-closest-points-to-origin/k_closest_points_to_origin.go

@@ -0,0 +1,10 @@
+package k_closest_points_to_origin
+
+import "sort"
+
+func kClosest(points [][]int, K int) [][]int {
+	sort.Slice(points, func(i, j int) bool {
+		return points[i][0]*points[i][0]+points[i][1]*points[i][1] < points[j][0]*points[j][0]+points[j][1]*points[j][1]
+	})
+	return points[:K]
+}

problems/k-closest-points-to-origin/k_closest_points_to_origin_test.go

@@ -0,0 +1,45 @@
+package k_closest_points_to_origin
+
+import (
+	"reflect"
+	"testing"
+)
+
+type caseType struct {
+	input    [][]int
+	k        int
+	expected [][]int
+}
+
+func TestKClosest(t *testing.T) {
+	tests := [...]caseType{
+		{
+			input: [][]int{
+				{1, 3},
+				{-2, 2},
+			},
+			k: 1,
+			expected: [][]int{
+				{-2, 2},
+			},
+		},
+		{
+			input: [][]int{
+				{3, 3},
+				{5, -1},
+				{-2, 4},
+			},
+			k: 2,
+			expected: [][]int{
+				{3, 3},
+				{-2, 4},
+			},
+		},
+	}
+	for _, tc := range tests {
+		output := kClosest(tc.input, tc.k)
+		if !reflect.DeepEqual(output, tc.expected) {
+			t.Fatalf("input: %v, output: %v, expected: %v", tc.input, output, tc.expected)
+		}
+	}
+}