RosettaCodeData/Task/Middle-three-digits/C/middle-three-digits-1.c
2023-07-01 13:44:08 -04:00

32 lines
621 B
C

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
// we return a static buffer; caller wants it, caller copies it
char * mid3(int n)
{
static char buf[32];
int l;
sprintf(buf, "%d", n > 0 ? n : -n);
l = strlen(buf);
if (l < 3 || !(l & 1)) return 0;
l = l / 2 - 1;
buf[l + 3] = 0;
return buf + l;
}
int main(void)
{
int x[] = {123, 12345, 1234567, 987654321, 10001, -10001,
-123, -100, 100, -12345, 1, 2, -1, -10, 2002, -2002, 0,
1234567890};
int i;
char *m;
for (i = 0; i < sizeof(x)/sizeof(x[0]); i++) {
if (!(m = mid3(x[i])))
m = "error";
printf("%d: %s\n", x[i], m);
}
return 0;
}