Array in string umwandeln c?

include <stdio.h>

int *a, *b;

void f(int x) {
  int i[3];
  i[0] = x;
  i[1] = x + 1;
  i[2] = x + 2;
  a = i;
}  

void g(int x) {
  int i[3];
  i[0] = x;
  i[1] = x + 1;
  i[2] = x + 2;
  b = i;
}  

int main() {
  f(1);
  printf("a = {%d,%d,%d}\n", a[0], a[1], a[2]);
  g(2);
  printf("a = {%d,%d,%d}\n", a[0], a[1], a[2]);
}

#include <stdio.h> /* fputs, puts */
#include <stdlib.h> /* calloc, EXIT_FAILURE, ... */
#include <stddef.h> /* size_t */

char * hexstr(
  const unsigned char * const buf,
  const size_t len
) {
  static const char * const hex = "0123456789ABCDEF";

  char * const str = calloc(len + 1, sizeof(* str));

  if (str) {
    for (size_t i = 0; i < len; ++i) {
      const unsigned char c = buf[i];

      str[i * 2] = hex[c >> 4];
      str[i * 2 + 1] = hex[c & 0xF];
    }
  }

  return str;
}

int main(void) {
  int result = EXIT_FAILURE;

  const unsigned char buf[] = { 0x23, 0x42, 0xBE, 0xEF };
  const size_t len = sizeof(buf) / sizeof(* buf);

  char * const str = hexstr(buf, len);

  if (str) {
    puts(str);
    free(str);

    result = EXIT_SUCCESS;
  } else {
    fputs("ERROR: Memory allocation failed.", stderr);
  }

  return result;
}

Hallo, in C gibt es keine Strings sonder nur Char-Pointer/Char-Arrays.

Einfach ein Char-Array mit genügend Platz erstellen und die Character aus den Originalarrays hintereinander reinkopieren.

sowas?

http://www.c-howto.de/tutorial/strings-zeichenketten/string-funktionen/strings-verketten/

oder in C++ die Merge Function