JAVA

merge without extra space

public void merge(int a1[], int a2[], int n1, int n2) {
        // code here
        int i = 0, j = 0, k = n1 - 1;
    while (i <= k && j < n2) {
        if (a1[i] < a2[j])
            i++;
        else {
            int temp = a2[j];
            a2[j] = a1[k];
            a1[k] = temp;
            j++;
            k--;
        }
    }
    Arrays.sort(a1);
    Arrays.sort(a2);
	
    }