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Merge pull request #318 from appleboy/patch-4

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fix: coding style and file format for chapter 7.
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2017-02-10 23:31:07 -05:00
committed by GitHub
parent 759272e928 e6d601d3a1
commit c5413075c1
15 changed files with 375 additions and 375 deletions
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44
eBook/exercises/chapter_7/array_value.go
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@@ -1,22 +1,22 @@
package main
import "fmt"
func main() {
var arr1 [5]int
for i:=0; i < len(arr1); i++ {
arr1[i] = i * 2
}
arr2 := arr1
arr2[2] = 100
for i:=0; i < len(arr1); i++ {
fmt.Printf("Array arr1 at index %d is %d\n", i, arr1[i])
}
fmt.Println()
for i:=0; i < len(arr2); i++ {
fmt.Printf("Array arr2 at index %d is %d\n", i, arr2[i])
}
}
package main
import "fmt"
func main() {
var arr1 [5]int
for i := 0; i < len(arr1); i++ {
arr1[i] = i * 2
}
arr2 := arr1
arr2[2] = 100
for i := 0; i < len(arr1); i++ {
fmt.Printf("Array arr1 at index %d is %d\n", i, arr1[i])
}
fmt.Println()
for i := 0; i < len(arr2); i++ {
fmt.Printf("Array arr2 at index %d is %d\n", i, arr2[i])
}
}

54
eBook/exercises/chapter_7/bubblesort.go
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@@ -1,27 +1,27 @@
// Q14_Bubblesort.go
package main
import (
"fmt"
)
func main() {
sla := []int{2, 6, 4, -10, 8, 89, 12, 68, -45, 37}
fmt.Println("before sort: ",sla)
// sla is passed via call by value, but since sla is a reference type
// the underlying slice is array is changed (sorted)
bubbleSort(sla)
fmt.Println("after sort: ",sla)
}
func bubbleSort(sl []int) {
// passes through the slice:
for pass:=1; pass < len(sl); pass++ {
// one pass:
for i:=0; i < len(sl) - pass; i++ { // the bigger value 'bubbles up' to the last position
if sl[i] > sl[i+1] {
sl[i], sl[i+1] = sl[i+1], sl[i]
}
}
}
}
// Q14_Bubblesort.go
package main
import (
"fmt"
)
func main() {
sla := []int{2, 6, 4, -10, 8, 89, 12, 68, -45, 37}
fmt.Println("before sort: ", sla)
// sla is passed via call by value, but since sla is a reference type
// the underlying slice is array is changed (sorted)
bubbleSort(sla)
fmt.Println("after sort: ", sla)
}
func bubbleSort(sl []int) {
// passes through the slice:
for pass := 1; pass < len(sl); pass++ {
// one pass:
for i := 0; i < len(sl)-pass; i++ { // the bigger value 'bubbles up' to the last position
if sl[i] > sl[i+1] {
sl[i], sl[i+1] = sl[i+1], sl[i]
}
}
}
}

36
eBook/exercises/chapter_7/fibonacci_array.go
View File

@@ -1,18 +1,18 @@
package main
import "fmt"
var fibs [50]int64
func main() {
fibs[0] = 1
fibs[1] = 1
for i:= 2; i < 50; i++ {
fibs[i] = fibs[i-1] + fibs[i-2]
}
for i:=0; i < 50; i++ {
fmt.Printf("The %d-th Fibonacci number is: %d\n", i, fibs[i])
}
}
package main
import "fmt"
var fibs [50]int64
func main() {
fibs[0] = 1
fibs[1] = 1
for i := 2; i < 50; i++ {
fibs[i] = fibs[i-1] + fibs[i-2]
}
for i := 0; i < 50; i++ {
fmt.Printf("The %d-th Fibonacci number is: %d\n", i, fibs[i])
}
}

44
eBook/exercises/chapter_7/fibonacci_funcarray.go
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@@ -1,22 +1,22 @@
package main
import "fmt"
var term = 15
func main() {
result := fibarray(term)
for ix, fib := range result {
fmt.Printf("The %d-th Fibonacci number is: %d\n", ix, fib)
}
}
func fibarray(term int) []int {
farr := make([]int, term)
farr[0], farr[1] = 1, 1
for i:= 2; i < term; i++ {
farr[i] = farr[i-1] + farr[i-2]
}
return farr
}
package main
import "fmt"
var term = 15
func main() {
result := fibarray(term)
for ix, fib := range result {
fmt.Printf("The %d-th Fibonacci number is: %d\n", ix, fib)
}
}
func fibarray(term int) []int {
farr := make([]int, term)
farr[0], farr[1] = 1, 1
for i := 2; i < term; i++ {
farr[i] = farr[i-1] + farr[i-2]
}
return farr
}

25
eBook/exercises/chapter_7/for_array.go
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@@ -1,13 +1,12 @@
package main
import "fmt"
func main() {
var arr [15]int
for i:=0; i < 15; i++ {
arr[i] = i
}
fmt.Println(arr) // [0 1 2 3 4 5 6 7 8 9 10 11 12 13 14]
}
package main
import "fmt"
func main() {
var arr [15]int
for i := 0; i < 15; i++ {
arr[i] = i
}
fmt.Println(arr) // [0 1 2 3 4 5 6 7 8 9 10 11 12 13 14]
}

46
eBook/exercises/chapter_7/insert_slice.go
View File

@@ -1,23 +1,23 @@
// insert_slice.go
package main
import (
"fmt"
)
func main() {
s := []string{"M", "N", "O", "P", "Q", "R"}
in := []string{"A", "B", "C"}
res := InsertStringSlice(s, in, 0) // at the front
fmt.Println(res) // [A B C M N O P Q R]
res = InsertStringSlice(s, in, 3) // [M N O A B C P Q R]
fmt.Println(res)
}
func InsertStringSlice(slice, insertion []string, index int) []string {
result := make([]string, len(slice) + len(insertion))
at := copy(result, slice[:index])
at += copy(result[at:], insertion)
copy(result[at:], slice[index:])
return result
}
// insert_slice.go
package main
import (
"fmt"
)
func main() {
s := []string{"M", "N", "O", "P", "Q", "R"}
in := []string{"A", "B", "C"}
res := InsertStringSlice(s, in, 0) // at the front
fmt.Println(res) // [A B C M N O P Q R]
res = InsertStringSlice(s, in, 3) // [M N O A B C P Q R]
fmt.Println(res)
}
func InsertStringSlice(slice, insertion []string, index int) []string {
result := make([]string, len(slice)+len(insertion))
at := copy(result, slice[:index])
at += copy(result[at:], insertion)
copy(result[at:], slice[index:])
return result
}

50
eBook/exercises/chapter_7/magnify_slice.go
View File

@@ -1,25 +1,25 @@
package main
import "fmt"
var s []int
func main() {
s = []int{1, 2, 3}
fmt.Println("The length of s before enlarging is:", len(s))
fmt.Println(s)
s = enlarge(s, 5)
fmt.Println("The length of s after enlarging is:", len(s))
fmt.Println(s)
}
func enlarge(s []int, factor int) []int {
ns := make([]int, len(s) * factor)
// fmt.Println("The length of ns is:", len(ns))
copy(ns, s)
//fmt.Println(ns)
s = ns
//fmt.Println(s)
//fmt.Println("The length of s after enlarging is:", len(s))
return s
}
package main
import "fmt"
var s []int
func main() {
s = []int{1, 2, 3}
fmt.Println("The length of s before enlarging is:", len(s))
fmt.Println(s)
s = enlarge(s, 5)
fmt.Println("The length of s after enlarging is:", len(s))
fmt.Println(s)
}
func enlarge(s []int, factor int) []int {
ns := make([]int, len(s)*factor)
// fmt.Println("The length of ns is:", len(ns))
copy(ns, s)
//fmt.Println(ns)
s = ns
//fmt.Println(s)
//fmt.Println("The length of s after enlarging is:", len(s))
return s
}

64
eBook/exercises/chapter_7/map_function.go
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@@ -1,32 +1,32 @@
package main
import "fmt"
func main() {
list := []int{0, 1, 2, 3, 4, 5, 6, 7}
mf := func(i int) int {
return i * 10
}
/*
result := mapFunc(mf, list)
for _, v := range result {
fmt.Println(v)
}
*/
println()
// shorter:
fmt.Printf("%v", mapFunc(mf, list) )
}
func mapFunc(mf func(int) int, list []int) ([]int) {
result := make([]int, len(list))
for ix, v := range list {
result[ix] = mf(v)
}
/*
for ix := 0; ix<len(list); ix++ {
result[ix] = mf(list[ix])
}
*/
return result
}
package main
import "fmt"
func main() {
list := []int{0, 1, 2, 3, 4, 5, 6, 7}
mf := func(i int) int {
return i * 10
}
/*
result := mapFunc(mf, list)
for _, v := range result {
fmt.Println(v)
}
*/
println()
// shorter:
fmt.Printf("%v", mapFunc(mf, list))
}
func mapFunc(mf func(int) int, list []int) []int {
result := make([]int, len(list))
for ix, v := range list {
result[ix] = mf(v)
}
/*
for ix := 0; ix<len(list); ix++ {
result[ix] = mf(list[ix])
}
*/
return result
}

80
eBook/exercises/chapter_7/min_max.go
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@@ -1,40 +1,40 @@
// Q13_1_max.go
package main
import (
"fmt"
"math"
)
func main() {
sl1 := []int{78, 34, 643, 12, 90, 492, 13, 2}
max := maxSlice(sl1)
fmt.Printf("The maximum is %d\n", max)
min := minSlice(sl1)
fmt.Printf("The minimum is %d\n", min)
}
func maxSlice(sl []int) (max int) {
for _, v := range sl {
if v > max {
max = v
}
}
return
}
func minSlice(sl []int) (min int) {
// min = int(^uint(0) >> 1)
min = math.MaxInt32
for _, v := range sl {
if v < min {
min = v
}
}
return
}
/* Output:
The maximum is 643
The minimum is 2
*/
// Q13_1_max.go
package main
import (
"fmt"
"math"
)
func main() {
sl1 := []int{78, 34, 643, 12, 90, 492, 13, 2}
max := maxSlice(sl1)
fmt.Printf("The maximum is %d\n", max)
min := minSlice(sl1)
fmt.Printf("The minimum is %d\n", min)
}
func maxSlice(sl []int) (max int) {
for _, v := range sl {
if v > max {
max = v
}
}
return
}
func minSlice(sl []int) (min int) {
// min = int(^uint(0) >> 1)
min = math.MaxInt32
for _, v := range sl {
if v < min {
min = v
}
}
return
}
/* Output:
The maximum is 643
The minimum is 2
*/

38
eBook/exercises/chapter_7/remove_slice.go
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@@ -1,19 +1,19 @@
// remove_slice.go
package main
import (
"fmt"
)
func main() {
s := []string{"M", "N", "O", "P", "Q", "R"}
res := RemoveStringSlice(s, 2, 4)
fmt.Println(res) // [M N Q R]
}
func RemoveStringSlice(slice []string, start, end int) []string {
result := make([]string, len(slice) - (end - start))
at := copy(result, slice[:start])
copy(result[at:], slice[end:])
return result
}
// remove_slice.go
package main
import (
"fmt"
)
func main() {
s := []string{"M", "N", "O", "P", "Q", "R"}
res := RemoveStringSlice(s, 2, 4)
fmt.Println(res) // [M N Q R]
}
func RemoveStringSlice(slice []string, start, end int) []string {
result := make([]string, len(slice)-(end-start))
at := copy(result, slice[:start])
copy(result[at:], slice[end:])
return result
}

32
eBook/exercises/chapter_7/split_string.go
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@@ -1,16 +1,16 @@
package main
import "fmt"
func main() {
str := "Google"
for i:=0; i <= len(str); i++ {
a, b := Split(str, i)
fmt.Printf("The string %s split at position %d is: %s / %s\n", str, i, a, b)
}
}
func Split(s string, pos int) (string, string) {
return s[0:pos], s[pos:]
}
package main
import "fmt"
func main() {
str := "Google"
for i := 0; i <= len(str); i++ {
a, b := Split(str, i)
fmt.Printf("The string %s split at position %d is: %s / %s\n", str, i, a, b)
}
}
func Split(s string, pos int) (string, string) {
return s[0:pos], s[pos:]
}

83
eBook/exercises/chapter_7/string_reverse.go
View File

@@ -1,41 +1,42 @@
package main
import "fmt"
func reverse(s string) string {
runes := []rune(s)
n, h := len(runes), len(runes)/2
for i:= 0; i < h; i ++ {
runes[i], runes[n-1-i] = runes[n-1-i], runes[i]
}
return string(runes)
}
func main() {
// reverse a string:
str := "Google"
sl := []byte(str)
var rev [100]byte
j := 0
for i:=len(sl)-1; i >= 0; i-- {
rev[j] = sl[i]
j++
}
str_rev := string(rev[:])
fmt.Printf("The reversed string is -%s-\n", str_rev)
// variant: "in place" using swapping
str2 := "Google"
sl2 := []byte(str2)
for i, j := 0, len(sl2) - 1; i < j; i, j = i+1, j-1 {
sl2[i], sl2[j] = sl2[j], sl2[i]
}
fmt.Printf("The reversed string is -%s-\n", string(sl2))
// variant: using [] int for runes (necessary for Unicode-strings!):
s := "My Test String!"
fmt.Println(s, " --> ", reverse(s))
}
/* Output:
The reversed string is -elgooG-
The reversed string is -elgooG-
My Test String! --> !gnirtS tseT yM
*/
package main
import "fmt"
func reverse(s string) string {
runes := []rune(s)
n, h := len(runes), len(runes)/2
for i := 0; i < h; i++ {
runes[i], runes[n-1-i] = runes[n-1-i], runes[i]
}
return string(runes)
}
func main() {
// reverse a string:
str := "Google"
sl := []byte(str)
var rev [100]byte
j := 0
for i := len(sl) - 1; i >= 0; i-- {
rev[j] = sl[i]
j++
}
str_rev := string(rev[:])
fmt.Printf("The reversed string is -%s-\n", str_rev)
// variant: "in place" using swapping
str2 := "Google"
sl2 := []byte(str2)
for i, j := 0, len(sl2)-1; i < j; i, j = i+1, j-1 {
sl2[i], sl2[j] = sl2[j], sl2[i]
}
fmt.Printf("The reversed string is -%s-\n", string(sl2))
// variant: using [] int for runes (necessary for Unicode-strings!):
s := "My Test String!"
fmt.Println(s, " --> ", reverse(s))
}
/* Output:
The reversed string is -elgooG-
The reversed string is -elgooG-
My Test String! --> !gnirtS tseT yM
*/

31
eBook/exercises/chapter_7/string_split2.go
View File

@@ -1,15 +1,16 @@
package main
import "fmt"
func main() {
str := "Google"
str2 := Split2(str)
fmt.Printf("The string %s transformed is: %s\n", str, str2)
}
func Split2(s string) string {
mid := len(s) / 2
return s[mid:] + s[:mid]
}
// Output: The string Google transformed is: gleGoo
package main
import "fmt"
func main() {
str := "Google"
str2 := Split2(str)
fmt.Printf("The string %s transformed is: %s\n", str, str2)
}
func Split2(s string) string {
mid := len(s) / 2
return s[mid:] + s[:mid]
}
// Output: The string Google transformed is: gleGoo

77
eBook/exercises/chapter_7/sum_array.go
View File

@@ -1,39 +1,38 @@
// leaving out the length 4 in [4] uses slice instead of an array
// which is generally better for performance
package main
import "fmt"
func main() {
// var a = [4]float32 {1.0,2.0,3.0,4.0}
var a = []float32 {1.0,2.0,3.0,4.0}
fmt.Printf("The sum of the array is: %f\n", Sum(a))
var b = []int {1, 2, 3, 4, 5}
sum, average := SumAndAverage(b)
fmt.Printf("The sum of the array is: %d, and the average is: %f", sum, average)
}
/*
func Sum(a [4]float32) (sum float32) {
for _, item := range a {
sum += item
}
return
}
*/
func Sum(a []float32) (sum float32) {
for _, item := range a {
sum += item
}
return
}
func SumAndAverage (a []int) (int, float32) {
sum := 0
for _, item := range a {
sum += item
}
return sum, float32(sum/len(a))
}
// leaving out the length 4 in [4] uses slice instead of an array
// which is generally better for performance
package main
import "fmt"
func main() {
// var a = [4]float32 {1.0,2.0,3.0,4.0}
var a = []float32{1.0, 2.0, 3.0, 4.0}
fmt.Printf("The sum of the array is: %f\n", Sum(a))
var b = []int{1, 2, 3, 4, 5}
sum, average := SumAndAverage(b)
fmt.Printf("The sum of the array is: %d, and the average is: %f", sum, average)
}
/*
func Sum(a [4]float32) (sum float32) {
for _, item := range a {
sum += item
}
return
}
*/
func Sum(a []float32) (sum float32) {
for _, item := range a {
sum += item
}
return
}
func SumAndAverage(a []int) (int, float32) {
sum := 0
for _, item := range a {
sum += item
}
return sum, float32(sum / len(a))
}

46
eBook/exercises/chapter_7/uniq.go
View File

@@ -1,23 +1,23 @@
// Q29_uniq.go
package main
import (
"fmt"
)
var arr []byte = []byte{'a','b','a','a','a','c','d','e','f','g'}
func main() {
arru := make([]byte,len(arr)) // this will contain the unique items
ixu := 0 // index in arru
tmp := byte(0)
for _, val := range arr {
if val!=tmp {
arru[ixu] = val
fmt.Printf("%c ", arru[ixu])
ixu++
}
tmp = val
}
// fmt.Println(arru)
}
// Q29_uniq.go
package main
import (
"fmt"
)
var arr []byte = []byte{'a', 'b', 'a', 'a', 'a', 'c', 'd', 'e', 'f', 'g'}
func main() {
arru := make([]byte, len(arr)) // this will contain the unique items
ixu := 0 // index in arru
tmp := byte(0)
for _, val := range arr {
if val != tmp {
arru[ixu] = val
fmt.Printf("%c ", arru[ixu])
ixu++
}
tmp = val
}
// fmt.Println(arru)
}