The purpose of this textbook, primarily aimed at first-year undergraduates in Programming, is, firstly, to teach students how to write a correct program, together with the proof of its correctness; and secondly, to show several basic methods of constructing effective algorithms. A well-structured problem/solution format is used, and the theory is presented as a sequence of problems. Solutions are concise, but ample explanations are given. All significant aspects of programming are covered.