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Q: Given two unsorted integer arrays a and b, where a has enough placeholder positions at the end to hold all elements of b, merge b into a and sort the final array in ascending order.
public void merge(int[] a, int[] b)
a = [5, 1, 3, 0, 0, 0]
b = [6, 2, 4]

result:
a = [1, 2, 3, 4, 5, 6]

public void merge(int[] a, int[] b) {
        // Copy b into the placeholder positions
        int m = a.length - b.length;
        for (int i = 0; i < b.length; i++) {
            a[m + i] = b[i];
        }

        // Sort the entire array
        Arrays.sort(a);
}