new files

Task/Binary-strings/C/binary-strings.c

@@ -0,0 +1,138 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+typedef struct str_t {
+	size_t len, alloc;
+	unsigned char *s;
+} bstr_t, *bstr;
+
+#define str_len(s) ((s)->len)
+bstr str_new(size_t len)
+{
+	bstr s = malloc(sizeof(bstr_t));
+	if (len < 8) len = 8;
+	s->alloc = len;
+	s->s = malloc(len);
+	s->len = 0;
+	return s;
+}
+
+void str_extend(bstr s)
+{
+	size_t ns = s->alloc * 2;
+	if (ns - s->alloc > 1024) ns = s->alloc + 1024;
+	s->s = realloc(s->s, ns);
+	s->alloc = ns;
+}
+
+void str_del(bstr s)
+{
+	free(s->s), free(s);
+}
+
+int str_cmp(bstr l, bstr r)
+{
+	int res, len = l->len;
+	if (len > r->len) len = r->len;
+
+	if ((res = memcmp(l->s, r->s, len))) return res;
+	return l->len > r->len ? 1 : -1;
+}
+
+bstr str_dup(bstr src)
+{
+	bstr x = str_new(src->len);
+	memcpy(x->s, src->s, src->len);
+	x->len = src->len;
+	return x;
+}
+
+bstr str_from_chars(const char *t)
+{
+	if (!t) return str_new(0);
+	size_t l = strlen(t);
+	bstr x = str_new(l + 1);
+	x->len = l;
+	memcpy(x->s, t, l);
+	return x;
+}
+
+void str_append(bstr s, unsigned char b)
+{
+	if (s->len >= s->alloc) str_extend(s);
+	s->s[s->len++] = b;
+}
+
+bstr str_substr(bstr s, int from, int to)
+{
+	if (!to) to = s->len;
+	if (from < 0) from += s->len;
+	if (from < 0 || from >= s->len)
+		return 0;
+	if (to < from) to = from + 1;
+	bstr x = str_new(to - from);
+	x->len = to - from;
+	memcpy(x->s, s->s + from, x->len);
+	return x;
+}
+
+bstr str_cat(bstr s, bstr s2)
+{
+	while (s->alloc < s->len + s2->len) str_extend(s);
+	memcpy(s->s + s->len, s2->s, s2->len);
+	s->len += s2->len;
+	return s;
+}
+
+void str_swap(bstr a, bstr b)
+{
+	size_t tz;
+	unsigned char *ts;
+	tz = a->alloc; a->alloc = b->alloc; b->alloc = tz;
+	tz = a->len; a->len = b->len; b->len = tz;
+	ts = a->s; a->s = b->s; b->s = ts;
+}
+
+bstr str_subst(bstr tgt, bstr pat, bstr repl)
+{
+	bstr tmp = str_new(0);
+	int i;
+	for (i = 0; i + pat->len <= tgt->len;) {
+		if (memcmp(tgt->s + i, pat->s, pat->len)) {
+			str_append(tmp, tgt->s[i]);
+			i++;
+		} else {
+			str_cat(tmp, repl);
+			i += pat->len;
+			if (!pat->len) str_append(tmp, tgt->s[i++]);
+		}
+	}
+	while (i < tgt->len) str_append(tmp, tgt->s[i++]);
+	str_swap(tmp, tgt);
+	str_del(tmp);
+	return tgt;
+}
+
+void str_set(bstr dest, bstr src)
+{
+	while (dest->len < src->len) str_extend(dest);
+	memcpy(dest->s, src->s, src->len);
+	dest->len = src->len;
+}
+
+int main()
+{
+	bstr s = str_from_chars("aaaaHaaaaaFaaaaHa");
+	bstr s2 = str_from_chars("___.");
+	bstr s3 = str_from_chars("");
+
+	str_subst(s, s3, s2);
+	printf("%.*s\n", s->len, s->s);
+
+	str_del(s);
+	str_del(s2);
+	str_del(s3);
+
+	return 0;
+}