-
Notifications
You must be signed in to change notification settings - Fork 0
/
String.c
385 lines (356 loc) · 9.08 KB
/
String.c
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
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
#include "String.h"
/*
Method to find the substring of given string.
*/
static Strings sub_string(Strings str, int start, int end){
Strings result = (Strings)malloc(sizeof(char) * (end - start));
if(result == NULL) {
return result;
}
int j = 0;
for(int i = start; i < end; i++){
result[j++] = str[i];
}
result[j] = '\0';
return result;
}
/*
Method to remove extra white space that is before or after the entered string.
*/
static Strings trim_string(Strings str) {
int i = strlen(str);
int j = 0;
while((j < i) && str[j] <= ' '){
j++;
}
while((j < i) && str[i-1] <= ' '){
i--;
}
return j > 0 || i < strlen(str) ? sub_string(str, j, i) : str;
}
/*
Method to find the number of words present after splitting.
*/
static int char_split_number(Strings str, Strings token) {
int count = 0;
Strings bufferArray = strdup(str);
Strings tokenStr = strtok(bufferArray, token);
while(tokenStr != NULL) {
count++;
tokenStr = strtok(NULL, token);
}
free(bufferArray);
return count;
}
/*
Method to split a string according to delimiters/tokes present and return array
of strings this uses strtok to split the string.
*/
static Strings* split_string(Strings str, Strings token) {
Strings *resultStrings = NULL;
Strings bufferString = strdup(str);
Strings tokenBuffer;
int count = 0;
resultStrings = (Strings *)malloc(sizeof(Strings) * (char_split_number(str, token) + 1));
if(resultStrings == NULL){
return resultStrings;
}
for(tokenBuffer = strtok(bufferString, token); tokenBuffer != NULL; count++) {
resultStrings[count] = strdup(tokenBuffer);
tokenBuffer = strtok(NULL, token);
}
free(bufferString);
resultStrings[count] = NULL;
return resultStrings;
}
/*
Method to replace substring with provided string.
*/
static Strings replace_string(Strings str, Strings replaceFromString, Strings stringToReplace) {
Strings result = NULL;
int i, count = 0;
int newStringLen = strlen(stringToReplace);
int oldStringLen = strlen(replaceFromString);
for(i = 0; str[i] != '\0'; i++) {
if(strstr(&str[i], replaceFromString) == &str[i]) {
count++;
i += oldStringLen - 1;
}
}
result = (Strings)malloc(i + count * (newStringLen - oldStringLen) + 1);
if(result == NULL){
return result;
}
i = 0;
while(*str) {
if(strstr(str, replaceFromString) == str) {
strcpy(&result[i], stringToReplace);
i += newStringLen;
str += oldStringLen;
} else {
result[i++] = *str++;
}
}
result[i] = '\0';
return result;
}
/*
Method to replace characters in a string.
*/
static Strings replace_char(Strings str, char replaceFromChar, char charToReplace) {
Strings resultString = strdup(str);
for(int i = 0; resultString[i] != '\0'; i++) {
if(resultString[i] == replaceFromChar) {
resultString[i] = charToReplace;
}
}
return resultString;
}
/*
Method to check if the string is empty ie has no characters in it.
*/
static int is_empty(Strings str) {
return str[0] == '\0' ? 1 : 0;
}
/*
Method to find the index of the occurrence of string from last.
*/
static int last_index_of_string(Strings str, Strings stringToFind, int startPosition) {
int count = strlen(stringToFind);
int i = startPosition == 0 ? strlen(str) : startPosition;
for(; i >= 0; i--) {
if(str[i] == stringToFind[count-1]) {
count --;
}
if(count == 0) {
break;
}
}
return i;
}
/*
Method to find the last index of the string given the start position.
*/
static int last_index_of_with_start(Strings str, Strings stringToFind, int startPosition) {
return last_index_of_string(str, stringToFind, startPosition);
}
/*
Method to find the last index string mentioned.
*/
static int last_index_of(Strings str, Strings stringToFind) {
return last_index_of_string(str, stringToFind, 0);
}
/*
Method to find the index of the substring
*/
static int index_of_string(Strings stringToFindFrom, Strings stringToFind, int startPosition) {
int count = 0;
int i = 0;
int stringToFindLen = strlen(stringToFind);
for(i = startPosition; stringToFindFrom[i] != '\0'; i++) {
if(stringToFindFrom[i] == stringToFind[count]) {
count++;
}
if(count == stringToFindLen) {
break;
}
}
if(count != stringToFindLen) {
return -1;
}
return (i - stringToFindLen + 1);
}
/*
Method to find the index of the substring starting from the desired position.
*/
static int index_of_with_start(Strings stringToFindFrom, Strings stringToFind, int startPosition) {
return index_of_string(stringToFindFrom, stringToFind, startPosition);
}
/*
Method to find the index of the substring starting from initial position.
*/
static int index_of(Strings stringToFindFrom, Strings stringToFind) {
return index_of_string(stringToFindFrom, stringToFind, 0);
}
/*
Method to generate hash code for the given string.
*/
static long hash_code(const Strings string) {
long hash = 0;
int stringLength = strlen(string);
if((hash == 0) && stringLength > 0) {
char arr[stringLength];
strcpy(arr, string);
for(int i = 0; i < stringLength + 1; i++) {
hash = 31 * hash + arr[i];
}
}
return hash;
}
/*
Method to convert string to upper case.
*/
static Strings to_upper(Strings string) {
int stringLength = strlen(string);
if(stringLength == 0) {
return (Strings)-1;
}
Strings s = strdup(string);
if(s == NULL){
return s;
}
for(int i = 0; s[i] != '\0'; i++) {
if(s[i] >= 'a' && s[i] <= 'z') {
s[i] = s[i] - 32;
}
}
return s;
}
/*
Method to convert string to lower case.
*/
static Strings to_lower(Strings string) {
int stringLength = strlen(string);
if(stringLength == 0) {
return (Strings)-1;
}
Strings s = strdup(string);
if(s == NULL){
return s;
}
for(int i = 0; s[i] != '\0'; i++) {
if(s[i] >= 'A' && s[i] <= 'Z') {
s[i] = s[i] + 32;
}
}
return s;
}
/*
Method to compare strings ignoring the case of string.
*/
static int equals_ignore_case(Strings str, Strings string) {
return hash_code(to_lower(str)) - hash_code(to_lower(string));
}
/*
Method to check if the entered string are equal.
*/
static int is_equal(Strings str, Strings string) {
return hash_code(str) - hash_code(string);
}
/*
Method to check if the given string ends with
given sub-string.
*/
static int end_with(Strings str, Strings string) {
int m = strlen(str);
int n = strlen(string);
int flag = -1;
int count = n;
for(int i = m; i >=0; i--) {
if(str[i] == string[count]) {
count--;
} else {
count = n;
}
if(count == 0) {
flag = 1;
break;
}
}
return (flag == 1) ? 1 : 0;
}
/*
Method to check if the string contains certain sub-string
*/
static int does_contains(Strings str, Strings string) {
int m = strlen(str);
int n = strlen(string);
int flag = -1;
int count = 0;
for(int i = 0; i < m; i++) {
if(str[i] == string[count]) {
count++;
} else {
count = 0;
}
if(count == n) {
flag = 1;
break;
}
}
return (flag == 1) ? 1 : 0;
}
/*
Method to concat strings if the size is found to be 0, it will return -1.
*/
static Strings concat_string(Strings str, Strings string) {
int i = strlen(string);
Strings charArr = (Strings)malloc(sizeof(char)*(strlen(str) + i + 1));
if((NULL == charArr) || (0 == i)) {
return (Strings)-1;
}
strcpy(charArr, str);
strcat(charArr, string);
return charArr;
}
/*
Method to compare two strings lexicographically
If both strings are equal, 0 is returned else it returns
positive or negative values.
*/
static int get_compare_to(Strings str, Strings string) {
int i = strlen(str);
int j = strlen(string);
char arr1[i];
char arr2[j];
strcpy(arr1, str);
strcpy(arr2, string);
int k = (int) fmin(i,j);
for(int m = 0; m < k; m++) {
int n = arr1[m];
int o = arr2[m];
if(n != o) {
return n - o;
}
}
return i - j;
}
/*
Method to get character at specified index
if the index is lower or equals than 0, there it will return 0
if the index is out of bound it will return 0
if there is no string is NULL, it will return 0.
*/
static char get_char_at(Strings str, int index) {
if(str != NULL && (index > 0 && index <= strlen(str))) {
return str[index - 1];
}
return -1;
}
/*
Method to initialize the default values for String struct.
*/
String *init() {
String *s = (String *) malloc(sizeof(String));
s->charAt = &get_char_at;
s->compareTo = &get_compare_to;
s->concat = &concat_string;
s->contains = &does_contains;
s->endsWith = &end_with;
s->hashCode = &hash_code;
s->equals = &is_equal;
s->equalsIgnoreCase = &equals_ignore_case;
s->toLowerCase = &to_lower;
s->toUpperCase = &to_upper;
s->indexOf = &index_of;
s->indexOfWithStart = &index_of_with_start;
s->isEmpty = &is_empty;
s->lastIndexOf = &last_index_of;
s->lastIndexOfWithStart = &last_index_of_with_start;
s->replaceChar = &replace_char;
s->replaceString = &replace_string;
s->split = &split_string;
s->trim = &trim_string;
s->subString = &sub_string;
return s == NULL ? NULL : s;
}