/**
 * Time Complexity : Comparision time : 3 * n/2 + 1
 */
public int[] findMinMax(int[] A){
    int n = A.length;
    if (n == 0) return null;
    int min = Integer.MAX_VALUE, max = Integer.MIN_VALUE;
    for (int i=0; i < n-1; i+=2){
        int smaller = A[i], bigger = A[i+1];
        if (A[i] > A[i+1){
            smaller = A[i+1];
            bigger = A[i];
        }
        if (smaller < min)
            min = smaller;
        if (bigger > max)
            max = bigger;
    }
    if (n % 2 == 1){
        if (A[n-1] < min)
            min = A[n-1];
        else (A[n-1] > max)
            max = A[n-1];
    }
    return new int[]{min, max};
}