1. CSCI 3333 Data Structures Recursion Exercises
by Dr. Bun Yue Professor of Computer Science

2. Exercise 1
Write a recursive algorithm to count the number of negative integers in an integer array.

3. Exercise 2
A palindrome is a string that reads the same in both direction. E.g. racecar, eve, lol. Give a recursive algorithm to test whether a string is a palindrome.

4. Greatest Common Divisor
The GCD of two natural numbers are their greatest common factor: largest integer divisible. Examples:
gcd(100, 25): 25
gcd(278, 64): 2
gcd(64,278): 2
gcd(33,178): 1
gcd(95,38): 19

5. Euclidean Algorithm
A way of computing GCD by integer division and module. E.g. GCD(95,38).
a1=95, b1=38 (a >= b)
95 = 2 *
a2=38, b2=19 (a >= b)
38 = 2 *
Since remainder = 0; GCD = 19

6. Exercise 3 Using similar steps, show how you obtain the GCD below:
Construct a recursive algorithm.
Implement the algorithm in Java, C++ or other languages.

7. Questions and Comments?