title: memcopy to change position of digits
body: <pre><code>#include &lt;stdlib.h&gt;
  #include &lt;stdio.h&gt;
  #include &lt;memory.h&gt;
  
  int main() {
      size_t n = 0;
      scanf("%Iu", &amp; n);
      int * p1 = (int * ) malloc(sizeof(int) * n); //dynamic memory allocation
      int * p2 = (int * ) malloc(sizeof(int) * n); //dynamic memory allocation
      for (int i = 0; i &lt; n; i++) {
        scanf("%d", &amp; p1[i]);
      }
      printf("\n");
      for (int i = 0; i &lt; n; i++) {
        scanf("%d", &amp; p2[i]); //input number users want
      }
      if ((n % 2) == 0) { //if n is even
        int c = n / 2;
        memcpy(p1 + c, p2, c * (sizeof(int))); //example:input 1234 and 5678
        printf("%d", p1); //          output 1278
      }
      free(p1); //return the memorys
      free(p2); //return the memorys
    } //end
  </code></pre>
  
  <p>aboved is my code. I want to show something under:</p>
  
  <p>input : 4 1 2 3 4 5 6 7 8<br>
  output: 1278</p>