Data Structures & Algorithms
Exam 1
Sample 1, 75 Minutes
Solutions
1. (a) The code is given below.
public void insertZero(int i, int k)
{// Insert k zeroes after element i.
// When i = -1, insert before element 0
if (k < 0 || i < -1 || i >= size)
throw new IllegalArgumentException("improper i
and/or k");
// make sure we have enough space
if (size + k > element.length)
{// get larger array
Object newArray = new Object [size + k];
System.arraycopy(element, 0, newArray, 0, size);
element = newArray;
}
// move k positions up
for (int j = size - 1; j > i; j--)
element[j+k] = element[j];
// fill with zeroes
for (int j = i + 1; j <= i + k; j++)
element[j] = zero;
size += k;
}
(b)
When an exception is thrown the complexity is Theta(1). Otherwise, it takes
O(size + k) time to increase the array size (if necessary). The second for loop
takes O(size)), and the third loop takes O(k) time. Therefore, the complexity
is O(size+k).
2. (a) The code is given below.
