From 7774aa901ec06a75747677b98a93093e8a5adbd7 Mon Sep 17 00:00:00 2001
From: hoang <giahoangth@gmail.com>
Date: Thu, 4 Jun 2020 16:44:11 +0700
Subject: [PATCH] review c2-m1

---
 c2-m1/reviewing/bubbleSort.go | 91 +++++++++++++++++++++++++++++++++++
 1 file changed, 91 insertions(+)
 create mode 100644 c2-m1/reviewing/bubbleSort.go

diff --git a/c2-m1/reviewing/bubbleSort.go b/c2-m1/reviewing/bubbleSort.go
new file mode 100644
index 0000000..5c8df79
--- /dev/null
+++ b/c2-m1/reviewing/bubbleSort.go
@@ -0,0 +1,91 @@
+package main
+
+import (
+	"fmt"
+	"strings"
+)
+
+func inputNumber() int {
+	var number int
+
+	for {
+		fmt.Print("Please enter a number: ")
+		var err error
+		if _, err = fmt.Scanln(&number); err == nil {
+			break
+		} else {
+			fmt.Println("Error:", err)
+		}
+	}
+
+	return number
+}
+
+func inputYesNo() string {
+	var answer string
+	for {
+		fmt.Print("Would you like to add more numbers?(y/n)")
+		var err error
+		if _, err = fmt.Scanln(&answer); err == nil {
+			answer = strings.ToLower(answer)
+			if answer == "y" || answer == "n" {
+				break
+			}
+		} else {
+			fmt.Println("Error:", err)
+		}
+	}
+	return answer
+}
+
+// [10]int would mean that type of the argument is an array => function gets a copy of it so can't modify it!
+// []int means that the type or argument is a slice => function can modify its elements but not size!
+// *[]int means that the type or argument is a pointer to slice => function can modify its size and its elements
+func inputNumbers(sequence *[]int) {
+	const maxNumbers = 10
+	for index := 0; index < maxNumbers; index++ {
+		*sequence = append(*sequence, inputNumber())
+		// fmt.Println("Sequence after adding a number:", *sequence)
+		if index == maxNumbers-1 {
+			fmt.Println("You've entered maximum (10) number of integers.")
+		} else {
+			answer := inputYesNo()
+			if answer == "n" {
+				break
+			}
+		}
+	}
+}
+
+// Swap function swaps i-th and i+1-th elements in the input sequence.
+func Swap(sequence []int, index int) {
+	if index >= len(sequence)-1 {
+		return
+	}
+	temp := sequence[index]
+	sequence[index] = sequence[index+1]
+	sequence[index+1] = temp
+}
+
+// BubbleSort uses Bubble Sort algorithm to sort input sequence of numbers.
+// This function only has to modify elements in the slice but not to change slice's size/length => we can pass []int
+func BubbleSort(sequence []int) {
+	lenght := len(sequence)
+
+	for i := 0; i < lenght; i++ {
+		for j := 0; j < lenght-1-i; j++ {
+			if sequence[j] > sequence[j+1] {
+				Swap(sequence, j)
+			}
+		}
+	}
+}
+
+func main() {
+	fmt.Println("Welcome to BubbleSort demo! You will be prompted to enter up to 10 numbers which will be sorted in the increasing order")
+	sequence := make([]int, 0, 10)
+	inputNumbers(&sequence)
+	fmt.Println("Original sequence:", sequence)
+	BubbleSort(sequence)
+	fmt.Println("Sorted sequence:", sequence)
+}