given an array, and an element to insert, and the position to insert this element,
return a new array with the element inserted
1,2,3,4,5,6 -> 1,2,3,15,4,5,6
1 public static void main(String[] args) {
2 int[] org = new int[]{1,2,3,4,5,6} ;
3 int[] res = insert(org, 15, 3);
4 print(res);
5 }
6
7 private static int[] insert(int[] org, int val, int insertIndex ) {
8 //note the way to create array: [# of items] = length; the last index = length - 1
9 int[] res = new int[org.length+1] ;
10 //find the ending index: anything <= remain the same
11 int pos = Math.min(insertIndex, org.length) ; //3
12 //[1,2,3] remain the same
13 for (int i = 0; i < pos ; i++) {
14 res[i] = org[i] ;
15 }
16 //create the new item
17 res[pos] = val ;
18 //the rest remain the same
19 for (int indexOld = pos; indexOld < org.length; indexOld++) {
20 res[indexOld+1] = org[indexOld] ;
21 }
22 /* the following is wrong: will jump one item
23 for (int i = pos+1; i < org.length ; i++) {
24 res[i] = org[i];
25 }
26 * */
27 return res ;
28 }
29 private static void print(int[] arr){
30 for (int i = 0; i <arr.length ; i++) {
31 System.out.println(arr[i]);
32 }
33 }
