>>466
#include <stdio.h>
#include <string.h>

int main(void)
{
char source[] = "ABCDEFAABCDABC";
char target[] = "ABC";

size_t l = strlen(target);
char *p;

puts(source);
puts(target);

while (p = strstr(source, target)) {
while (p[0] = p[l]) {
p++;
}
}

puts(source);

return 0;
}