208 lines
50 KiB
C
208 lines
50 KiB
C
test
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#include <assert.h>
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#include <string.h>
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#include <stdlib.h>
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#include "str.h"
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#include "util.h"
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#define INIT_SZ 20
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// Внутренняя функция,
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// позволяет убедиться что строка может вместить как минимум newsz символов
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void
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_str_ensure(str *s, int newsz)
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{
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int tmp;
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newsz += 1; // добавляем единичку чтобы влез нулевой байт
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if (newsz < s->capacity)
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return;
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tmp = s->capacity * 2;
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if (tmp > newsz) {
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newsz = tmp;
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}
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s->ptr = xrealloc(s->ptr, newsz);
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s->capacity = newsz;
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}
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void
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str_init(str *s)
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{
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assert(s);
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s->len = 0;
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s->capacity = INIT_SZ;
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s->ptr = xmalloc(s->capacity);
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s->ptr[0] = '\0';
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}
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void
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str_deinit(str *s)
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{
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if (s->ptr)
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free(s->ptr);
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s->ptr = NULL;
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s->len = 0;
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s->capacity = 0;
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}
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void
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str_init_data(str *s, const char *initial)
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{
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assert(s && initial);
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int len = strlen(initial);
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s->len = len;
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s->capacity = len + 1;
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if (s->capacity < INIT_SZ) {
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s->capacity = INIT_SZ;
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}
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s->ptr = xmalloc(s->capacity);
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strcpy(s->ptr, initial);
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}
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char *
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str_data(str *s)
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{
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assert(s);
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return s->ptr;
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}
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void
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str_set(str *s, char *cstr)
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{
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assert(s && cstr);
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int len = strlen(cstr);
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_str_ensure(s, len);
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strcpy(s->ptr, cstr);
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s->len = len;
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}
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str
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str_copy(str *s)
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{
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assert(s);
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str new_str;
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str_init(&new_str);
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_str_ensure(&new_str, s->len);
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strcpy(new_str.ptr, s->ptr);
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new_str.len = s->len;
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return new_str;
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}
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int
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str_count(str *s, char ch)
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{
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assert(s);
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int count = 0;
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for (int i = 0; i < s->len; i++) {
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if (s->ptr[i] == ch) {
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count++;
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}
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}
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return count;
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}
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void
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str_append(str *s, char *cstr)
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{
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assert(s && cstr);
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str_append_n(s, cstr, strlen(cstr));
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}
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void
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str_append_n(str *s, char *cstr, int len)
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{
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assert(s && cstr);
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_str_ensure(s, s->len + len);
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memcpy(s->ptr + s->len, cstr, len);
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s->len += len;
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s->ptr[s->len] = '\0';
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}
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void
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str_shrink(str *s, int len)
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{
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assert(s && len >= 0);
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if (len > s->len) {
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len = s->len;
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}
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s->len = len;
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s->ptr[s->len] = '\0';
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}
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int
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str_find(str *s, char *substr)
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{
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assert(s && substr);
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char *p = strstr(s->ptr, substr);
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if (p == NULL)
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return -1;
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return p - s->ptr;
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}
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str
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str_sub(str *s, int start_idx, int length)
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{
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assert(s && start_idx >= 0 && length >= 0);
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str s2;
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str_init(&s2);
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if (start_idx >= s->len) {
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return s2; // пустая строка
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}
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if (start_idx + length > s->len) {
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length = s->len - start_idx;
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}
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_str_ensure(&s2, length);
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memcpy(s2.ptr, s->ptr + start_idx, length);
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s2.ptr[length] = '\0';
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s2.len = length;
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return s2;
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}
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// Hint: you can create temporary string object!
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int
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str_replace(str *s, char *substr, char *replacement)
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{
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assert(s && substr && replacement);
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int count = 0;
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str result;
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str_init(&result);
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int substr_len = strlen(substr);
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int replacement_len = strlen(replacement);
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char *current = s->ptr;
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char *found;
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while ((found = strstr(current, substr)) != NULL) {
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// Добавляем часть до найденной подстроки
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int prefix_len = found - current;
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if (prefix_len > 0) {
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str_append_n(&result, current, prefix_len);
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}
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// Добавляем замену
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str_append_n(&result, replacement, replacement_len);
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current = found + substr_len;
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count++;
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}
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// Добавляем оставшуюся часть строки
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if (*current != '\0') {
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str_append(&result, current);
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}
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// Заменяем исходную строку результатом
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free(s->ptr);
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s->ptr = result.ptr;
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s->len = result.len;
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s->capacity = result.capacity;
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return count;
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} |