#include <stdio.h>
 
void cat_data(int *data1, const int *data2, int len2);
 
int main(void) 
{
  int data1[7] ={1,2,3,4,5,6,7};
  int data2[5]={8,9,10,11,12};
  int len1 = sizeof(data1)/sizeof(data1[0]);
  int len2 = sizeof(data2)/sizeof(data2[0]);
 
  cat_data(data1,data2,len2);
  for (int i = 0;i<7;i++){
  printf("data1[%d] = %d\n", i, data1[i] );
  }
  return 0;
}
 
void cat_data(int *data1, const int *data2, int len2)
{
data1 = data1 +2;
while(len2--){
*data1++ = *data2++;
}
}

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