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fixed implementation error; not all matches were found (e.g. xy in xxy) 

there is no optimization, the book version is used thus the rename
master
Tibor Bizjak 2023-07-23 23:22:08 +02:00
parent 8ebefb2974
commit 09fb685153
1 changed files with 10 additions and 13 deletions
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23
k&r/04-funcs-and-prog-struct/04-find/find-opt.c → k&r/04-funcs-and-prog-struct/04-find/find-book.c
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@ -1,21 +1,19 @@
#include <stdio.h> #include <stdio.h>
#include <string.h>
#define MAXLINE 1000 /* maximum input line length */ #define MAXLINE 1000 /* maximum input line length */
int getln(char line[], int lim); int getln(char line[], int lim);
int strindex(char source[], char searchfor[], int slen); int strindex(char source[], char searchfor[]);
/* find: prints lines containing pattern, returns number of matching lines */ /* find: prints lines containing pattern, returns number of matching lines */
int find(char *pattern, char lineno_flag, char except_flag) int find(char *pattern, char lineno_flag, char except_flag)
{ {
char line[MAXLINE]; char line[MAXLINE];
int found = 0; int found = 0;
int slen = strlen(pattern);
long lineno; long lineno;
for (lineno = 1; getln(line, MAXLINE) > 0; lineno++) for (lineno = 1; getln(line, MAXLINE) > 0; lineno++)
if ((strindex(line, pattern, slen) >= 0) != except_flag) { if ((strindex(line, pattern) >= 0) != except_flag) {
if (lineno_flag) if (lineno_flag)
printf("%ld:", lineno); printf("%ld:", lineno);
printf("%s", line); printf("%s", line);
@ -36,15 +34,14 @@ int getln(char *s, int lim)
} }
/* strindex: return index of t in s, -1 if none */ /* strindex: return index of t in s, -1 if none */
int strindex(char s[], char t[], int slen) int strindex(char s[], char t[])
{ {
int i, j; int i, j, k;
for (i = 0; s[i]; i++) {
for (i = j = 0; s[i]; i++) for (j=i, k=0; t[k] && s[j] == t[k]; j++, k++)
if (s[i] != t[j]) ;
j = 0; if (k > 0 && !t[k])
else if (++j == slen) { // found match return i;
return i - slen + 1; }
}
return -1; return -1;
} }