quadratic equation - bubble / insertion / selection sort

Author: gcaggia

Diff for: quadratic_equation.go

@@ -0,0 +1,34 @@
+package main
+
+import (
+	"../golang-algorithms/utils"
+	"fmt"
+	"strconv"
+)
+
+func quadraticEquation(a, b, c int) (solution string)  {
+	delta := b * b - 4 * a * c
+	if delta < 0 {
+		solution = "The discriminant is negative, then there are no real roots"
+	} else if delta == 0 {
+		solution = "The discriminant is zero, then there is exactly one real root x=-" +
+			strconv.Itoa(b) + "/2*" + strconv.Itoa(a)
+	} else {
+		solution = "The discriminant is positive, then there are two distinct roots: " +
+			" x1=-" + strconv.Itoa(b) + "-sqrt(" + strconv.Itoa(delta) +
+			")/2*"  + strconv.Itoa(a) +
+			" and x2=-" + strconv.Itoa(b) + "+sqrt(" + strconv.Itoa(delta) +
+			")/2*"  + strconv.Itoa(a)
+	}
+	return
+}
+
+
+func main() {
+	fmt.Println("The Standard Form of a Quadratic Equation is ax2 + bx + c = 0")
+	fmt.Println("Please choose a, b, c")
+	a := utils.NumberInput("a: ")
+	b := utils.NumberInput("b: ")
+	c := utils.NumberInput("c: ")
+	fmt.Println(quadraticEquation(a, b ,c))
+}

Diff for: sort_bubble.go

@@ -0,0 +1,22 @@
+package main
+
+import (
+	"fmt"
+	utils "../golang-algorithms/utils"
+)
+
+func bubbleSort(arr[] int)  {
+	for  flag := true ; flag == true ;  {
+		flag = false
+		for i := 0; i < len(arr) - 1; i++ {
+			if arr[i] > arr[i+1] { arr[i], arr[i+1], flag = arr[i+1], arr[i], true }
+		}
+	}
+}
+
+func main() {
+	arr := utils.RandomIntArray(10)
+	fmt.Println("Array before: ", arr)
+	bubbleSort(arr)
+	fmt.Println("Array after:  ", arr)
+}

Diff for: sort_insertion.go

@@ -0,0 +1,21 @@
+package main
+
+import (
+	"fmt"
+	utils "../golang-algorithms/utils"
+)
+
+func insertionSort(arr[] int)  {
+	for i := 1; i < len(arr) ; i++  {
+		for j:= i; j > 0 && arr[j-1] > arr[j]; j-- {
+			arr[j-1], arr[j] = arr[j], arr[j-1]
+ 		}
+	}
+}
+
+func main() {
+	arr := utils.RandomIntArray(10)
+	fmt.Println("Array before: ", arr)
+	insertionSort(arr)
+	fmt.Println("Array after:  ", arr)
+}

Diff for: sort_selection.go

@@ -0,0 +1,23 @@
+package main
+
+import (
+	"fmt"
+	utils "../golang-algorithms/utils"
+)
+
+func selectionSort(arr[] int)  {
+	for i := 0 ; i < len(arr) ; i++  {
+		min := i
+		for j := i+1; j < len(arr); j++ {
+			if arr[j] < min { min = j }
+		}
+		if min != i { arr[i], arr[min] = arr[min], arr[i] }
+	}
+}
+
+func main() {
+	arr := utils.RandomIntArray(10)
+	fmt.Println("Array before: ", arr)
+	selectionSort(arr)
+	fmt.Println("Array after:  ", arr)
+}

Diff for: utils/library.go

@@ -1,6 +1,20 @@
 package utils
 
+import (
+	"math/rand"
+	"time"
+)
+
 func Bool2Float(b bool) float64 {
 	if b { return 1 }
 	return 0
 }
+
+func RandomIntArray(size int) (arr[] int) {
+	for i := 0; i< size;i++  {
+		rand.Seed(time.Now().UTC().UnixNano())
+		n:= rand.Intn(1000) - rand.Intn(1000)
+		arr = append(arr, n)
+	}
+	return
+}