Introduction to Computer Science

Lecture by lecture outline

1. We presented two algorithms for calculating the greatest common divisor of two integers. The first of these is based directly on the definition of the greatest common divisor, and implemented in Example1GCD_Naive.java. The second uses the Euclidean algorithm and is implemented in Example2GCD_Euclidean.java.

2. We proved that the Euclidean algorithm terminates on any input and that it yields the correct result. We also explained why its runtime is much better than that of the naive algorithm. We started going over the Java programs implementing the two algorithms, and explained a few basic elements of the language: variables, assignment statements, the type int, for loops and if statements. We also discussed the function Math.random().

3. We presented the printing commands System.out.print() and System.out.println(), talked about all integer and real types, and gave more examples of conditional statements and loops, including while loops and nested loops.

4. We discussed infinite loops and the data types char, boolean and String .