-
Notifications
You must be signed in to change notification settings - Fork 6
/
palindrome.go
204 lines (177 loc) · 4.15 KB
/
palindrome.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
// Package str :: palindrome.go
package str
import (
"fmt"
"reflect"
"strconv"
"unicode"
u "github.com/dockerian/go-coding/utils"
)
// Palindrome interface
type Palindrome interface {
GetData() string
IsPalindrome() bool
}
// PalindromeNumber struct
type PalindromeNumber struct {
input uint64
}
// PalindromeString struct
type PalindromeString struct {
input string
}
// GetData returns input data
func (p *PalindromeNumber) GetData() string {
if p == nil {
return ""
}
return strconv.FormatUint(p.input, 10)
}
// GetData returns input data
func (p *PalindromeString) GetData() string {
if p == nil {
return ""
}
return p.input
}
// GetSubstring returns the longest palindromic substring
func (p *PalindromeString) GetSubstring() string {
if p == nil {
return ""
}
return GetPalindromicSubstring(p.input)
}
// GetPalindromicSubstring returns the longest palindromic substring
func GetPalindromicSubstring(str string) string {
if len(str) <= 0 {
return ""
}
var end = len(str) - 1
var x, y int
for k := 0; k < end; k++ {
var i, j int
var m, n = k + 2, k + 1
var continued bool
if m < end && str[k] == str[m] {
continued = str[k] == str[n]
i, j = k, m
}
if n < end && str[k] == str[n] {
continued = true
i, j = k, n
}
if j > 0 {
if continued {
for i > 0 && str[i-1] == str[k] {
i--
}
for j < end && str[k] == str[j+1] {
j++
}
}
for i > 0 && j < end && str[i-1] == str[j+1] {
i--
j++
}
if j-i > y-x {
x, y = i, j
}
}
if y-x > 2*(end-k) {
u.Debug("break: x = %v, y = %v ['%v']; k = %v, end = %v in '%v'\n",
x, y, str[x:y+1], k, end, str)
break
}
}
return str[x : y+1]
}
// IsPalindrome checks if an input number is palindrome
func (p *PalindromeNumber) IsPalindrome() bool {
if p == nil {
return false
}
return IsPalindromeNumber(p.input)
}
// IsPalindrome checks if an input string is palindrome
func (p *PalindromeString) IsPalindrome() bool {
if p == nil {
return false
}
return IsPalindromeString(p.input)
}
// IsPalindromePhase checks if an input string is palindrome phase
func (p *PalindromeString) IsPalindromePhase() bool {
if p == nil {
return false
}
return IsPalindromePhase(p.input)
}
// IsPalindrome checks if interface{} is palindrome
func IsPalindrome(input interface{}) (bool, error) {
v := reflect.ValueOf(input)
// switch v.Kind() case reflect.int32
switch input.(type) {
case int, int8, int16, int32, int64,
uint, uint8, uint16, uint32, uint64:
if v.Int() <= 0 {
return IsPalindromeNumber(uint64(-v.Int())), nil
}
return IsPalindromeNumber(v.Uint()), nil
case string:
return IsPalindromeString(v.String()), nil
}
return false, fmt.Errorf("unsupported type: %v", v.Kind())
}
// IsPalindromeNumber checks if an input number is palindrome
func IsPalindromeNumber(input uint64) bool {
var number = input
var numberReversed uint64
for number != 0 {
numberReversed = numberReversed*10 + number%10
number /= 10
}
return input == numberReversed
}
// IsPalindromePhase checks if an input string is palindrome phase
func IsPalindromePhase(input string) bool {
if len(input) == 0 {
return false
}
var runes = []rune{}
for _, char := range input {
runes = append(runes, char)
}
//u.Debug("input = %v, runes = %+v\n", input, runes)
var valid = false
var bound = len(runes) - 1
for i, j := 0, bound; i <= bound && j >= i; i++ {
for i <= bound && !u.IsDigitOrLetter(runes[i]) {
i++
}
//u.Debug("runes[%v] = %c, runes[%v] = %c, bound = %v\n", i, runes[i], j, runes[j], bound)
for j > 1 && !u.IsDigitOrLetter(runes[j]) {
j--
}
//u.Debug("runes[%v] = %c, runes[%v] = %c, bound = %v\n", i, runes[i], j, runes[j], bound)
if i <= bound && j > i {
if unicode.ToLower(runes[i]) != unicode.ToLower(runes[j]) {
u.Debug("break: runes[%v] = %c != runes[%v] = %c, input = %v\n",
i, runes[i], j, runes[j], input)
return false
}
valid = true
}
j--
}
return valid
}
// IsPalindromeString checks if an input string is palindrome
func IsPalindromeString(input string) bool {
var size = len(input)
for i := 0; i < size>>1; i++ {
if input[i] != input[size-1-i] {
return false
}
}
return true
}