code kata 230808

time_complexity/main_test.go

@@ -0,0 +1,87 @@
+package main
+
+import "testing"
+
+func binarySearch(arr []int, l, r, target int) int {
+	if l > r {
+		return -1
+	}
+	mid := l + (r-l)/2
+	if arr[mid] == target {
+		return mid
+	} else if arr[mid] > target {
+		return binarySearch(arr, l, mid-1, target)
+	} else {
+		return binarySearch(arr, mid+1, r, target)
+	}
+}
+
+func TestBinarySearch(t *testing.T) {
+	type input struct {
+		arr    []int
+		l      int
+		r      int
+		target int
+	}
+	tt := []struct {
+		name  string
+		input input
+		want  int
+	}{
+		{"first", input{
+			arr:    []int{2, 3, 4, 5, 7},
+			l:      0,
+			r:      4,
+			target: 5,
+		}, 3},
+		{"second", input{
+			arr:    []int{2, 3, 4, 5, 7},
+			l:      0,
+			r:      4,
+			target: 2,
+		}, 0},
+		{"third", input{
+			arr:    []int{2, 3, 4, 5, 7},
+			l:      0,
+			r:      4,
+			target: 7,
+		}, 4},
+	}
+
+	for _, tc := range tt {
+		t.Run(tc.name, func(t *testing.T) {
+			got := binarySearch(tc.input.arr, tc.input.l, tc.input.r, tc.input.target)
+			if got != tc.want {
+				t.Errorf("binarySearch(%v) = %d, want %d", tc.input, got, tc.want)
+			}
+		})
+	}
+}
+
+func sum(n int) int {
+	if n == 0 {
+		return 0
+	}
+	return n + sum(n-1)
+}
+
+func TestSum(t *testing.T) {
+	tt := []struct {
+		name  string
+		input int
+		want  int
+	}{
+		{"1", 1, 1},
+		{"2", 2, 3},
+		{"3", 3, 6},
+		{"4", 4, 10},
+	}
+	for _, tc := range tt {
+		t.Run(tc.name, func(t *testing.T) {
+			got := sum(tc.input)
+			if got != tc.want {
+				t.Errorf("sum(%d)=%d, want %d", tc.input, got, tc.want)
+			}
+		})
+	}
+}