homework

exercises/main.go

@@ -0,0 +1,67 @@
+package main
+
+import (
+	"fmt"
+	"math"
+)
+
+func partition(s []int, pivot int) (i int) {
+	l, r, p := 0, len(s)-1, 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]
+
+	}
+}
+
+func fromNtoOne(n int) {
+	if n <= 0 {
+		return
+	}
+	fromNtoOne(n - 1)
+	fmt.Println(n)
+	fromNtoOne(n - 1)
+	//Time / Space complexity O(n) - linear func
+}
+func fibonacci(n int) int {
+	if n <= 1 {
+		return n
+	}
+	return fibonacci(n-1) + fibonacci(n-2)
+	//Time / Space complexity O(n) - linear func
+}
+func isPowerOfTwo(n int) {
+	n = n / 2
+	if n == 2 {
+		fmt.Println("TRUE")
+	} else if n > 2 {
+		isPowerOfTwo(n)
+	} else {
+		fmt.Println("FALSE")
+	}
+	//Time / Space complexity O(n) - logarithmic func, beacuse we divide by two every iteration i suppose
+}
+func sumOfDigits(n int) int {
+	if n == 0 {
+		return 0
+	}
+	return n%10 + sumOfDigits(n/10)
+	//Time / Space complexity O(n) - logarithmic func, same as previous but i am not sure beacuse of %
+
+}
+func sliceMax(s []int) int {
+	if len(s) == 1 {
+		return s[0]
+	}
+	return int(math.Max(float64(s[0]), float64(sliceMax(s[1:]))))
+	//Time / Space complexity ? can even we count complexity of something thats is not really  an algorithm
+
+}

exercises/main_test.go

@@ -0,0 +1,68 @@
+package main
+
+import (
+	"testing"
+)
+
+func TestRearrange(t *testing.T) {
+	for _, tc := range []struct {
+		name  string
+		s     []int
+		pivot int
+		want  int
+	}{
+		{"no repeated elements", []int{8, 4, 1, 0, 5, 9, 3, 7, 2, 6}, 4, 5},
+		{"repeated elements", []int{9, 6, 1, 7, 5, 9, 6, 5, 2, 6}, 9, 4},
+		{"empty left side", []int{9, 6, 1, 7, 5, 9, 6, 5, 2, 0}, 9, 0},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			got := partition(tc.s, tc.pivot)
+			areLess(tc.s[:got], tc.s[got], t)
+			if got != tc.want {
+				t.Errorf("got = %v, want = %v", got, tc.want)
+			}
+		})
+	}
+}
+
+func areLess(s []int, p int, t *testing.T) {
+	for _, e := range s {
+		if e > p {
+			t.Errorf("%v > %v", e, p)
+		}
+	}
+}
+
+func TestSumOfDigits(t *testing.T) {
+	for _, tc := range []struct {
+		input int
+		want  int
+	}{
+		{0, 0},
+		{123, 6},
+		{1234567890, 45},
+		{666, 18},
+		{-12, -3}, // considering this test func counts both numbers as negative -1 + -2
+		{-123, -6},
+	} {
+		if got := sumOfDigits(tc.input); got != tc.want {
+			t.Errorf("numSum(%v)   got = %v, want = %v", tc.input, got, tc.want)
+		}
+	}
+}
+func TestSliceMax(t *testing.T) {
+	for _, tc := range []struct {
+		input []int
+		want  int
+	}{
+		//{nil, 0}, FAIL
+		{[]int{1}, 1},
+		{[]int{1, 34, 45, -67}, 45},
+		{[]int{1, 1, 1, 1, 1, 1}, 1},
+		{[]int{-5, -8, -90, -4567}, -5},
+	} {
+		if got := sliceMax(tc.input); got != tc.want {
+			t.Errorf("numSum(%v)   got = %v, want = %v", tc.input, got, tc.want)
+		}
+	}
+}