Question from codility test

Write a function:

`class Solution { public int solution(int[] A); } `

that, given an array A of N integers, returns the smallest positive integer (greater than 0) that does not occur in A.

For example, given A = [1, 3, 6, 4, 1, 2], the function should return 5.

Given A = [1, 2, 3], the function should return 4.

Given A = [−1, −3], the function should return 1.

Write an efficient algorithm for the following assumptions:

N is an integer within the range [1..100,000];

each element of array A is an integer within the range [−1,000,000..1,000,000].

This is what I have tried

```
class Solution {
public int solution(int[] A) {
int minValue = A[0];
do {
for (int i = 0; i < A.length; i++) {
if (A[i] < minValue) {
minValue = A[i];
}
}
} while (contains(A, ++minValue) == true);
return minValue;
}
public static boolean contains(int[] arr, int item) {
for (int n : arr) {
if (item == n) {
return true;
}
}
return false;
}
public static void main(String[] args) {
Solution s = new Solution();
int[] intArray = new int[]{1, 3, 6, 4, 1, 2};
int ans = s.solution(intArray);
System.out.println(ans);
}
}
```

I get infinity loop, no result displayed.

Can someone please point me out what is wrong here ?