diff options
Diffstat (limited to 'reverse.c')
-rw-r--r-- | reverse.c | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/reverse.c b/reverse.c new file mode 100644 index 0000000..a038df2 --- /dev/null +++ b/reverse.c @@ -0,0 +1,42 @@ +#include <u.h> +#include <libc.h> + +char * +reverse(char *s, int n) +{ + int i; + char tmp; + + for(i = 0; i < n/2; i++){ + tmp = s[i]; + s[i] = s[n-i-1]; + s[n-i-1] = tmp; + } + return s; +} + +char * +reversep(char *s, int n) +{ + char *bp, *ep; + char tmp; + + for(bp = s, ep = s+n-1; bp != ep; bp++, ep--){ + tmp = *bp; + *bp = *ep; + *ep = tmp; + } + return s; +} + +void +main() +{ + char s[] = "hello"; + + print("%s → ", s); + print("%s\n", reverse(s, strlen(s))); + print("%s → ", s); + print("%s\n", reversep(s, strlen(s))); + exits(0); +} |