hw

exercises/main.go

@@ -0,0 +1,73 @@
+package main
+
+import "fmt"
+
+func partitions(s []int, pivot int) (i int) {
+	l, r := 0, len(s)-1
+	p := s[pivot]
+	for {
+		for s[l] < p {
+			l++
+		}
+		for s[r] > p {
+			r--
+		}
+		if l >= r {
+			return l
+		}
+		s[l], s[r] = s[r], s[l]
+		r--
+		// код писал я сам, по памяти с того что разбирали на уроке
+	}
+}
+
+func fibonacci(n int) int {
+	if n <= 1 {
+		return n
+	}
+	return fibonacci(n-1) + fibonacci(n-2)
+	// time complexity = O(1)
+	// space complaxity = O(1)
+}
+func powerof2(n int) bool {
+	return (n & (n - 1)) == 0
+	// time complexity = O(1)
+	// space complaxity = O(1)
+}
+func sumdigits(n int, sum int) int {
+	if n != 0 {
+		i := n % 10
+		sum += i
+		return sumdigits(n/10, sum)
+	}
+	return sum
+	//time complexity = O(n) or maybe O(log n) idk
+	// space complaxity = O(n)
+}
+
+func maxnum(n []int, i int, max int, max2 int) (int, int) {
+	if len(n) != i {
+		if n[i] > max {
+			max2 = max
+			max = n[i]
+		}
+		i++
+		return maxnum(n, i, max, max2)
+	}
+	return max, max2
+	//time complexity = O(n)
+	// space complaxity = O(n)
+}
+
+func main() {
+	s := []int{9, 6, 1, 7, 5, 9, 6, 5, 2, 6}
+	i := partitions(s, 9)
+	fmt.Println("Output: ", i, s)
+	for i := 0; i <= 6; i++ {
+		fmt.Print(fibonacci(i), " ")
+	}
+	fmt.Println("\n", powerof2(256))
+	fmt.Println(sumdigits(8999999991, 0))
+	n := []int{10, 2, -3, 14}
+	fmt.Println(maxnum(n, 0, 0, 0))
+}

exercises/main_test.go

@@ -0,0 +1,108 @@
+package main
+
+import (
+	"testing"
+)
+
+type Input struct {
+	s []int
+	p int
+}
+
+func areLess(s []int, p int, t *testing.T) {
+	for _, el := range s {
+		if el > p {
+			t.Errorf("%v > %v", el, p)
+		}
+	}
+}
+
+func TestRearrange(t *testing.T) {
+	for _, tc := range []struct {
+		name  string
+		input Input
+		want  int
+	}{
+		{"case1", Input{[]int{8, 4, 1, 0, 5, 9, 3, 7, 2, 6}, 4}, 5},
+		{"case2", Input{[]int{9, 6, 1, 7, 5, 9, 6, 5, 2, 6}, 9}, 4},
+		{"case3", Input{[]int{9, 6, 1, 7, 5, 9, 6, 5, 2, 0}, 9}, 0},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+
+			input := tc.input
+
+			got := partitions(input.s, input.p)
+
+			areLess(input.s[:got], input.s[got], t)
+
+			if got != tc.want {
+				t.Errorf("got = %v, want = %v", got, tc.want)
+			}
+		})
+	}
+}
+
+// func Testfibonacci(t* testing.T){
+// 	for _, tc := range []struct{
+// 		n int
+// 		want int
+// 	}{
+// 		{0, 1, 1, 2, 3, 5, 8}
+// 	}
+// 	}
+// }
+func TestIspowerof2(t *testing.T) {
+	for _, tc := range []struct {
+		n    int
+		want bool
+	}{
+		{512, true},
+		{128, true},
+		{9, false},
+		{3, false},
+		{64, true},
+		{31, false},
+	} {
+		if got := powerof2(tc.n); got != tc.want {
+			t.Errorf("powerof2(%v)   got = %v, want = %v", tc.n, got, tc.want)
+		}
+	}
+}
+
+func TestSumdigits(t *testing.T) {
+	for _, tc := range []struct {
+		n    int
+		sum  int
+		want int
+	}{
+		{333, 0, 9},
+		{321, 0, 6},
+		{21, 0, 3},
+		{10000, 0, 1},
+		{420, 0, 6},
+		{228, 0, 12},
+	} {
+		if got := sumdigits(tc.n, tc.sum); got != tc.want {
+			t.Errorf("numSum(%v)   got = %v, want = %v", tc.n, got, tc.want)
+		}
+	}
+}
+
+func TestMaxnum(t *testing.T) {
+	for _, tc := range []struct {
+		n     []int
+		i     int
+		max   int
+		max2  int
+		wmax  int
+		wmax2 int
+	}{
+		{[]int{1000, 1001, -100, 1}, 0, 0, 0, 1001, 1000},
+		{[]int{1, -3, 99, 675}, 0, 0, 0, 675, 99},
+		{[]int{10, 11, -100, 1}, 0, 0, 0, 11, 10},
+	} {
+		if max, max2 := maxnum(tc.n, tc.i, tc.max, tc.max2); max != tc.wmax || max2 != tc.wmax2 {
+			t.Errorf("numSum(%v) got = %v, %v, want = %v, %v", tc.n, max, max2, tc.wmax, tc.wmax2)
+		}
+	}
+}