c++ - Insert item to array -

i have 3 arrays contains 5 elements each (max size 5). wanted insert item, e.g, position 7. end result item should placed in 2nd array @ index 2 , 4th array created 1 element (from last item of 3rd array).

                                result array1                          array1     - item1 (position 0)            - item1 (position 0)     - item2 (position 1)            - item2 (position 1)     - item3 (position 2)            - item3 (position 2)     - item4 (position 3)            - item4 (position 3)     - item5 (position 4)            - item5 (position 4) array2                          array2     - item1 (position 5)            - item1 (position 5)     - item2 (position 6)            - item2 (position 6)     - item3 (position 7)            - item3 (position 7) -> new_item     - item4 (position 8)            - item4 (position 8)     - item5 (position 9)            - item5 (position 9) array3                          array3     - item1 (position 10)           - item1 (position 10)     - item2 (position 11)           - item2 (position 11)     - item3 (position 12)           - item3 (position 12)     - item4 (position 13)           - item4 (position 13)     - item5 (position 14)           - item5 (position 14)                                 array4                                     - item1 (position 15) 

and, if wanted item @ position 12, result should item3 of array3.

how can in c++?

you haven't told real problem, here's outline of general solution. access position 13:

unsigned int n = 13;  // zero-based index find array. unsigned int = n/5;  // zero-based index of element within array. unsigned int j = n%5; 

for insertion, function insert item x @ location k , return last item (which had removed make room):

int insert(item *a, item x, unsigned int k) {   item ret = a[4];    for(unsigned int j=4; j>k; --j)     a[j]=a[j-1];   a[k] = x;   return(ret); } 

so if have 3 arrays, insert item x @ position 7:

item y;  y = insert(array2, x, 2); y = insert(array3, y, 0); 

now create new array4 whatever method like, , set array4[0]=y.