Answer:
To implement the copy method, we need to create a new 2D array with the same dimensions as the input array A, and then copy the values from A into the new array. Here's one way to do it:
static int[][] copy(int[][] A) {
int[][] B = new int[A.length][];
for (int i = 0; i < A.length; i++) {
B[i] = new int[A[i].length];
for (int j = 0; j < A[i].length; j++) {
B[i][j] = A[i][j];
}
}
return B;
}
This method creates a new 2D array B with the same number of rows as A. For each row of A, it creates a new array with the same length as that row, and then copies the values from A into the new array. Finally, it returns the new array B.
Here's the complete code with the copy method added:
public class ArrayCopy {
public static void main (String[] argv) {
int[][] A = {
{1},
{2, 1},
{3, 2, 1},
{4, 3, 2, 1},
{5, 4, 3, 2, 1}
};
print (A);
int[][] B = copy (A);
print (B);
}
static void print (int[][] X) {
for (int i=0; i<X.length; i++) {
for (int j=0; j<X[i].length; j++) {
System.out.print (" " + X[i][j]);
}
System.out.println ();
}
}
static int[][] copy(int[][] A) {
int[][] B = new int[A.length][];
for (int i = 0; i < A.length; i++) {
B[i] = new int[A[i].length];
for (int j = 0; j < A[i].length; j++) {
B[i][j] = A[i][j];
}
}
return B;
}
}
Hope this helps!