Given two sorted integer arrays a[] and b[], merge b[] into a[] as one sorted array.

MergeSortedArrays.java

public void merge(int[] a, int m, int[] b, int n) {
        int i = m - 1;
        int j = n - 1;
        int k = m + n - 1;

        while(i >= 0 && j >= 0) 
            a[k--] = a[i] > b[j] ? a[i--] : b[j--];

        while(i >= 0)
            a[k--] = a[i--];

        while(j >= 0)
            a[k--] = b[j--];

        return;
}