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add: array exercises

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Inanc Gumus
2018-12-05 15:02:03 +03:00
parent 25c15716b6
commit 91e17cbeb3
27 changed files with 690 additions and 113 deletions
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0
14-arrays/05-array-literal-example/main.go → 14-arrays/05-examples-3-hipsters-love-bookstore/main.go
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2
14-arrays/TODO.md
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@ -1,2 +0,0 @@
- [ ] add challenge link to the moodly's resources
- [ ] add exercises 1 and 2 after the array basics quiz

15
14-arrays/exercises/00-name/main.go
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@ -1,15 +0,0 @@
package main
// ---------------------------------------------------------
// EXERCISE: Name
// ?
//
// NOTE
// ?
//
// EXPECTED OUTPUT
// ?
// ---------------------------------------------------------
func main() {
}

4
14-arrays/exercises/00-name/solution/main.go
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@ -1,4 +0,0 @@
package main
func main() {
}

27
14-arrays/exercises/05-fix/main.go Normal file
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@ -0,0 +1,27 @@
package main
// ---------------------------------------------------------
// EXERCISE: Fix
//
// 1. Uncomment the code
// 2. And fix the problems
// 3. BONUS: Simplify the code
// ---------------------------------------------------------
func main() {
// var names [3]string = [3]string{
// "Einstein" "Shepard"
// "Tesla"
// }
// var books [5]string = [5]string{
// "Kafka's Revenge",
// "Stay Golden",
// "",
// "",
// ""
// }
// fmt.Printf("%q\n", names)
// fmt.Printf("%q\n", books)
}

11
14-arrays/exercises/05-fix/solution/main.go Normal file
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@ -0,0 +1,11 @@
package main
import "fmt"
func main() {
names := [...]string{"Einstein", "Shepard", "Tesla"}
books := [5]string{"Kafka's Revenge", "Stay Golden"}
fmt.Printf("%q\n", names)
fmt.Printf("%q\n", books)
}

34
14-arrays/exercises/06-compare/main.go Normal file
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@ -0,0 +1,34 @@
package main
import "fmt"
// ---------------------------------------------------------
// EXERCISE: Compare the Arrays
//
// 1. Uncomment the code
// 2. Fix the problems so that arrays become comparable
//
// EXPECTED OUTPUT
// true
// true
// false
// ---------------------------------------------------------
func main() {
// week := [...]string{"Monday", "Tuesday"}
// wend := [4]string{"Saturday", "Sunday"}
// fmt.Println(week != wend)
// evens := [...]int{2, 4, 6, 8, 10}
// evens2 := [...]int32{2, 4, 6, 8, 10}
// fmt.Println(evens == evens2)
// Use : uint8 for one of the arrays instead of byte here.
// Remember: Aliased types are the same types.
image := [5]byte{'h', 'i'}
var data [5]byte
fmt.Println(data == image)
}

22
14-arrays/exercises/06-compare/solution/main.go Normal file
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@ -0,0 +1,22 @@
package main
import "fmt"
func main() {
week := [...]string{"Monday", "Tuesday"}
wend := [...]string{"Saturday", "Sunday"}
fmt.Println(week != wend)
evens := [...]int{2, 4, 6, 8, 10}
evens2 := [...]int{2, 4, 6, 8, 10}
fmt.Println(evens == evens2)
// Use : uint8 for one of the arrays instead of byte here.
// Remember: Aliased types are the same types.
image := [5]uint8{'h', 'i'}
var data [5]byte
fmt.Println(data == image)
}

31
14-arrays/exercises/07-assign/main.go Normal file
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@ -0,0 +1,31 @@
package main
// ---------------------------------------------------------
// EXERCISE: Assign the Arrays
//
// 1. Create an array named books
// 2. Add book titles to the array
// 3. Create two more copies of the array named: upper and lower
// 4. Change the book titles to uppercase in the upper array only
// 5. Change the book titles to lowercase in the lower array only
// 6. Print all the arrays
// 7. Observe that the arrays are not connected when they're copied.
//
// NOTE
// Check out the strings package, it has functions to convert letters to
// upper and lower cases.
//
// BONUS
// Invent your own arrays with different types other than string,
// and do some manipulations on them.
//
// EXPECTED OUTPUT
// Note: Don't worry about the book titles here, you can use any title.
//
// books: ["Kafka's Revenge" "Stay Golden" "Everythingship"]
// upper: ["KAFKA'S REVENGE" "STAY GOLDEN" "EVERYTHINGSHIP"]
// lower: ["kafka's revenge" "stay golden" "everythingship"]
// ---------------------------------------------------------
func main() {
}

21
14-arrays/exercises/07-assign/solution/main.go Normal file
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@ -0,0 +1,21 @@
package main
import (
"fmt"
"strings"
)
func main() {
books := [...]string{"Kafka's Revenge", "Stay Golden", "Everythingship"}
upper, lower := books, books
for i := range books {
upper[i] = strings.ToUpper(upper[i])
lower[i] = strings.ToLower(lower[i])
}
fmt.Printf("books: %q\n", books)
fmt.Printf("upper: %q\n", upper)
fmt.Printf("lower: %q\n", lower)
}

25
14-arrays/exercises/08-wizard-printer/main.go Normal file
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@ -0,0 +1,25 @@
package main
// ---------------------------------------------------------
// EXERCISE: Wizard Printer
//
// In this exercise, your goal is to display a few famous scientists
// in a pretty table.
//
// 1. Create a multi-dimensional array
// 2. In each inner array, store the scientist's name, lastname and his/her
// nickname
// 3. Print their information in a pretty table using a loop.
//
// EXPECTED OUTPUT
// First Name Last Name Nickname
// ==================================================
// Albert Einstein time
// Isaac Newton apple
// Stephen Hawking blackhole
// Marie Curie radium
// Charles Darwin fittest
// ---------------------------------------------------------
func main() {
}

26
14-arrays/exercises/08-wizard-printer/solution/main.go Normal file
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@ -0,0 +1,26 @@
package main
import (
"fmt"
"strings"
)
func main() {
names := [...][3]string{
{"First Name", "Last Name", "Nickname"},
{"Albert", "Einstein", "emc2"},
{"Isaac", "Newton", "apple"},
{"Stephen", "Hawking", "blackhole"},
{"Marie", "Curie", "radium"},
{"Charles", "Darwin", "fittest"},
}
for i := range names {
n := names[i]
fmt.Printf("%-15s %-15s %-15s\n", n[0], n[1], n[2])
if i == 0 {
fmt.Println(strings.Repeat("=", 50))
}
}
}

41
14-arrays/exercises/09-currency-converter/main.go Normal file
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@ -0,0 +1,41 @@
package main
// ---------------------------------------------------------
// EXERCISE: Currency Converter
//
// In this exercise, you're going to display currency exchange ratios
// against USD.
//
// 1. Declare a few constants with iota. They're going to be the keys
// of the array.
//
// 2. Create an array that contains the conversion ratios.
//
// You should use keyed elements and the contants you've declared before.
//
// 3. Get the USD amount to be converted from the command line.
//
// 4. Handle the error cases for missing or invalid input.
//
// 5. Print the exchange ratios.
//
// EXPECTED OUTPUT
// go run main.go
// Please provide the amount to be converted.
//
// go run main.go invalid
// Invalid amount. It should be a number.
//
// go run main.go 10.5
// 10.50 USD is 9.24 EUR
// 10.50 USD is 8.19 GBP
// 10.50 USD is 1186.71 JPY
//
// go run main.go 1
// 1.00 USD is 0.88 EUR
// 1.00 USD is 0.78 GBP
// 1.00 USD is 113.02 JPY
// ---------------------------------------------------------
func main() {
}

37
14-arrays/exercises/09-currency-converter/solution/main.go Normal file
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@ -0,0 +1,37 @@
package main
import (
"fmt"
"os"
"strconv"
)
func main() {
const (
EUR = iota
GBP
JPY
)
rates := [...]float64{
EUR: 0.88,
GBP: 0.78,
JPY: 113.02,
}
args := os.Args[1:]
if len(args) != 1 {
fmt.Println("Please provide the amount to be converted.")
return
}
amount, err := strconv.ParseFloat(args[0], 64)
if err != nil {
fmt.Println("Invalid amount. It should be a number.")
return
}
fmt.Printf("%.2f USD is %.2f EUR\n", amount, rates[EUR]*amount)
fmt.Printf("%.2f USD is %.2f GBP\n", amount, rates[GBP]*amount)
fmt.Printf("%.2f USD is %.2f JPY\n", amount, rates[JPY]*amount)
}

24
14-arrays/exercises/0x-hipsters-love-search/main.go
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@ -1,24 +0,0 @@
// For more tutorials: https://blog.learngoprogramming.com
//
// Copyright © 2018 Inanc Gumus
// Learn Go Programming Course
// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
//
package main
// search for books in hipster's love
// ---------------------------------------------------------
// EXERCISE: Name
// ?
//
// NOTE
// ?
//
// EXPECTED OUTPUT
// ?
// ---------------------------------------------------------
func main() {
}

56
14-arrays/exercises/10-hipsters-love-search/main.go Normal file
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@ -0,0 +1,56 @@
// For more tutorials: https://blog.learngoprogramming.com
//
// Copyright © 2018 Inanc Gumus
// Learn Go Programming Course
// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
//
package main
// ---------------------------------------------------------
// EXERCISE: Hipster's Love Search Engine
//
// Your goal is to let people search for books of Hipster's Love Bookstore.
//
// 1. Create an array with these book titles:
// Kafka's Revenge
// Stay Golden
// Everythingship
// Kafka's Revenge 2nd Edition
//
// 2. Get the search query from the command-line argument
//
// 3. Search for the books in the books array
//
// 4. When the programs find the book, print it.
// 5. Otherwise, print that the book doesn't exist.
//
// 6. Handle the errors.
//
// RESTRICTION:
// + The search should be case insensitive.
//
// EXPECTED OUTPUT
// go run main.go
// Tell me a book title
//
// go run main.go STAY
// Search Results:
// + Stay Golden
//
// go run main.go sTaY
// Search Results:
// + Stay Golden
//
// go run main.go "Kafka's Revenge"
// Search Results:
// + Kafka's Revenge
// + Kafka's Revenge 2nd Edition
//
// go run main.go void
// Search Results:
// We don't have the book: "void"
// ---------------------------------------------------------
func main() {
}

23
14-arrays/exercises/0x-hipsters-love-search/solution/main.go → 14-arrays/exercises/10-hipsters-love-search/solution/main.go
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@ -13,27 +13,24 @@ import (
"strings"
)
const yearly = 4
func main() {
var books [yearly]string
books := [4]string{
"Kafka's Revenge",
"Stay Golden",
"Everythingship",
"Kafka's Revenge 2nd Edition",
}
books[0] = "Kafka's Revenge"
books[1] = "Stay Golden"
books[2] = "Everythingship"
books[3] += books[0] + " 2nd Edition"
if len(os.Args) != 2 {
args := os.Args[1:]
if len(args) != 1 {
fmt.Println("Tell me a book title")
return
}
query := os.Args[1]
query := strings.ToLower(args[0])
fmt.Println("Search Results:")
fmt.Println("---------------")
var found bool
for _, v := range books {
if strings.Contains(strings.ToLower(v), query) {
fmt.Println("+", v)
@ -42,6 +39,6 @@ func main() {
}
if !found {
fmt.Printf("We don't have that book: %q\n", query)
fmt.Printf("We don't have the book: %q\n", query)
}
}

42
14-arrays/exercises/11-average/main.go Normal file
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@ -0,0 +1,42 @@
// For more tutorials: https://blog.learngoprogramming.com
//
// Copyright © 2018 Inanc Gumus
// Learn Go Programming Course
// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
//
package main
// ---------------------------------------------------------
// EXERCISE: Find the Average
//
// Your goal is to fill an array with numbers and find the average.
//
// 1. Get the numbers from the command-line.
//
// 2. Create an array and assign the given numbers to that array.
//
// 3. Print the given numbers and their average.
//
// RESTRICTION
// + Maximum 5 numbers can be provided
// + If one of the arguments are not a valid number, skip it
//
// EXPECTED OUTPUT
// go run main.go
// Please tell me numbers (maximum 5 numbers).
//
// go run main.go 1 2 3 4 5 6
// Please tell me numbers (maximum 5 numbers).
//
// go run main.go 1 2 3 4 5
// Your numbers: [1 2 3 4 5]
// Average: 3
//
// go run main.go 1 a 2 b 3
// Your numbers: [1 0 2 0 3]
// Average: 2
// ---------------------------------------------------------
func main() {
}

42
14-arrays/exercises/11-average/solution/main.go Normal file
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@ -0,0 +1,42 @@
// For more tutorials: https://blog.learngoprogramming.com
//
// Copyright © 2018 Inanc Gumus
// Learn Go Programming Course
// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
//
package main
import (
"fmt"
"os"
"strconv"
)
func main() {
args := os.Args[1:]
if l := len(args); l == 0 || l > 5 {
fmt.Println("Please tell me numbers (maximum 5 numbers).")
return
}
var (
sum float64
nums [5]float64
total float64
)
for i, v := range args {
n, err := strconv.ParseFloat(v, 64)
if err != nil {
continue
}
total++
nums[i] = n
sum += n
}
fmt.Println("Your numbers:", nums)
fmt.Println("Average:", sum/total)
}

41
14-arrays/exercises/12-sorter/main.go Normal file
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@ -0,0 +1,41 @@
package main
// ---------------------------------------------------------
// EXERCISE: Number Sorter
//
// Your goal is to sort the given numbers from the command-line.
//
// 1. Get the numbers from the command-line.
//
// 2. Create an array and assign the given numbers to that array.
//
// 3. Sort the given numbers and print them.
//
// RESTRICTION
// + Maximum 5 numbers can be provided
// + If one of the arguments are not a valid number, skip it
//
// HINTS
// + You can use the bubble-sort algorithm to sort the numbers.
// Please watch this: https://youtu.be/nmhjrI-aW5o?t=7
//
// + When swapping for elements, do not check for the last element.
// Or, you will receive this error:
// "panic: runtime error: index out of range"
//
// EXPECTED OUTPUT
// go run main.go
// Please give me up to 5 numbers.
//
// go run main.go 6 5 4 3 2 1
// Sorry. Go arrays are fixed. So, for now, I'm only supporting sorting 5 numbers...
//
// go run main.go 5 4 3 2 1
// [1 2 3 4 5]
//
// go run main.go 5 4 a c 1
// [0 0 1 4 5]
// ---------------------------------------------------------
func main() {
}

58
14-arrays/exercises/12-sorter/solution/main.go Normal file
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@ -0,0 +1,58 @@
// For more tutorials: https://blog.learngoprogramming.com
//
// Copyright © 2018 Inanc Gumus
// Learn Go Programming Course
// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
//
package main
import (
"fmt"
"os"
"strconv"
)
func main() {
args := os.Args[1:]
switch l := len(args); {
case l == 0:
fmt.Println("Please give me up to 5 numbers.")
return
case l > 5:
fmt.Println("Sorry. Go arrays are fixed.",
"So, for now, I'm only supporting sorting 5 numbers...")
return
}
var nums [5]float64
// fill the array with the numbers
for i, v := range args {
n, err := strconv.ParseFloat(v, 64)
if err != nil {
// skip if it's not a valid number
continue
}
nums[i] = n
}
/*
check whether it's the last element or not:
i < len(nums)-1
check whether the next number is greater than the current one, if so, swap it:
v > nums[i+1]
*/
for range nums {
for i, v := range nums {
if i < len(nums)-1 && v > nums[i+1] {
nums[i], nums[i+1] = nums[i+1], nums[i]
}
}
}
fmt.Println(nums)
}

48
14-arrays/exercises/13-word-finder/main.go Normal file
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@ -0,0 +1,48 @@
package main
// ---------------------------------------------------------
// EXERCISE: Word Finder
//
// Your goal is to search for the words inside the corpus.
//
// Note: This exercise is similar to the previous word finder program:
// https://github.com/inancgumus/learngo/tree/master/13-loops/10-word-finder-labeled-switch
//
// 1. Get the search query from the command-line (it can be multiple words)
//
// 2. Filter these words, do not search for them:
// and, or, was, the, since, very
//
// To do this, use an array for the filtered words.
//
// 3. Print the words found.
//
// RESTRICTION
// + The search and the filtering should be case insensitive
//
// HINT
// + strings.Fields function converts a given string a slice.
// You can find its example in the worder finder program that I've mentioned
// above.
//
// EXPECTED OUTPUT
// go run main.go
// Please give me a word to search.
//
// go run main.go and was
//
// go run main.go AND WAS
//
// go run main.go cat beginning
// #2 : "cat"
// #11: "beginning"
//
// go run main.go Cat Beginning
// #2 : "cat"
// #11: "beginning"
// ---------------------------------------------------------
const corpus = "lazy cat jumps again and again and again since the beginning this was very important"
func main() {
}

48
14-arrays/exercises/13-word-finder/solution/main.go Normal file
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@ -0,0 +1,48 @@
// For more tutorials: https://blog.learngoprogramming.com
//
// Copyright © 2018 Inanc Gumus
// Learn Go Programming Course
// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
//
package main
import (
"fmt"
"os"
"strings"
)
const corpus = "lazy cat jumps again and again and again since the beginning this was very important"
func main() {
query := os.Args[1:]
if len(query) == 0 {
fmt.Println("Please give me a word to search.")
return
}
filter := [...]string{
"and", "or", "was", "the", "since", "very",
}
words := strings.Fields(strings.ToLower(corpus))
queries:
for _, q := range query {
q = strings.ToLower(q)
for _, v := range filter {
if q == v {
continue queries
}
}
for i, w := range words {
if q == w {
fmt.Printf("#%-2d: %q\n", i+1, w)
break
}
}
}
}

13
14-arrays/exercises/IDEAS.md
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@ -1,13 +0,0 @@
# Array Exercises
- get data from command-line
- into a fixed array; see how it blows beyond its len
- add items
- get items
- check the length
- reverse the array
- shuffle the items
- find the first item that contains x
- find the last item that contains y
- find the duplicate items

22
14-arrays/exercises/README.md
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@ -1,6 +1,6 @@
# Array Exercises
## Basic Exercises
## Exercises Level I - Basics
1. **[Declare Empty Arrays](https://github.com/inancgumus/learngo/tree/master/14-arrays/exercises/01-declare-empty)**
@ -10,10 +10,24 @@
4. **[Refactor to Ellipsis](https://github.com/inancgumus/learngo/tree/master/14-arrays/exercises/04-ellipsis)**
5. **[Fix](https://github.com/inancgumus/learngo/tree/master/14-arrays/exercises/05-fix)**
6. **[Compare the Arrays](https://github.com/inancgumus/learngo/tree/master/14-arrays/exercises/06-compare)**
7. **[Assign the Arrays](https://github.com/inancgumus/learngo/tree/master/14-arrays/exercises/07-assign)**
---
## Program Exercises
## Exercises Level II
????. **[text](https://github.com/inancgumus/learngo/tree/master/14-arrays/exercises/)**
1. **[Wizard Printer](https://github.com/inancgumus/learngo/tree/master/14-arrays/exercises/08-wizard-printer)**
?
2. **[Currency Converter](https://github.com/inancgumus/learngo/tree/master/14-arrays/exercises/09-currency-converter)**
3. **[Hipster's Bookstore Search Engine](https://github.com/inancgumus/learngo/tree/master/14-arrays/exercises/10-hipsters-love-search)**
4. **[Find the Average](https://github.com/inancgumus/learngo/tree/master/14-arrays/exercises/11-average)**
5. **[Number Sorter](https://github.com/inancgumus/learngo/tree/master/14-arrays/exercises/12-sorter)**
6. **[Word Finder](https://github.com/inancgumus/learngo/tree/master/14-arrays/exercises/13-word-finder)**

38
etc/stratch/main.go
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@ -1,42 +1,4 @@
package main
import "fmt"
func main() {
students := [...][3]float64{
{5, 6, 1},
{9, 8, 4},
}
var sum float64
for _, grades := range students {
for _, grade := range grades {
sum += grade
}
}
const N = float64(len(students) * len(students[0]))
fmt.Printf("Avg Grade: %g\n", sum/N)
// students := [2][3]float64{
// [3]float64{5, 6, 1},
// [3]float64{9, 8, 4},
// }
// var sum float64
// sum += students[0][0] + students[0][1] + students[0][2]
// sum += students[1][0] + students[1][1] + students[1][2]
// const N = float64(len(students) * len(students[0]))
// fmt.Printf("Avg Grade: %g\n", sum/N)
// student1 := [3]float64{5, 6, 1}
// student2 := [3]float64{9, 8, 4}
// var sum float64
// sum += student1[0] + student1[1] + student1[2]
// sum += student2[0] + student2[1] + student2[2]
// const N = float64(len(student1) * 2)
// fmt.Printf("Avg Grade: %g\n", sum/N)
}

52
x-tba/17-strings-revisited/exercises/_exp/fromarrays/main.go Normal file
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@ -0,0 +1,52 @@
package main
import (
"fmt"
"strings"
)
// ---------------------------------------------------------
// EXERCISE: Assign the Arrays
//
// 1. Create an array named books
// 2. Add book titles to the array
// 3. Create two more copies of the array named: upper and lower
// 4. Change the book titles to uppercase in the upper array only
// 5. Change the book titles to lowercase in the lower array only
// 6. Print all the arrays
//
// NOTE
// Check out the strings package, it has function to convert cases to
// upper and lower cases.
//
// BONUS
// 1. Invent your own arrays with different types other than string,
// and do some manipulations on them.
//
// 👉 THISSSS--------------------------------------------------------
// 2. Find some Turkish book titles and do the same upper, lowercase conversion
// for them.
//
// Here are some books: https://www.goodreads.com/group/bookshelf/417154-bilimkurgu-kul-b?shelf=read
//
// Note: You'd need to use special functions to convert the Turkish letters.
// They're in the strings package as well.
//
// EXPECTED OUTPUT
// ?
// ---------------------------------------------------------
func main() {
books := [...]string{"Kafka's Revenge", "Stay Golden", "Everythingship"}
upper, lower := books, books
for i := range books {
upper[i] = strings.ToUpper(upper[i])
lower[i] = strings.ToLower(lower[i])
}
fmt.Printf("books: %q\n", books)
fmt.Printf("upper: %q\n", upper)
fmt.Printf("lower: %q\n", lower)
}