Blueprint First: Designing Algorithms with Pseudocode and Flowcharts

Hi, I'm Byte. Before any programmer types real code, the smart move is to design the algorithm first. Computer scientist Donald Knuth established five properties every true algorithm must have — and you need all five, not just three. First, finiteness: the algorithm must eventually stop for every possible input. Second, definiteness: every step must be precisely and unambiguously specified — no guessing allowed. Third, input: the algorithm accepts zero or more values from an outside source. Fourth, output: it produces at least one result. Fifth, effectiveness: every step must be basic enough to actually be carried out in a finite amount of time. We express algorithms in two language-independent ways. Pseudocode is structured plain English that mimics code without obeying any one language's grammar. It uses three control structures: SEQUENCE (do steps in order), SELECTION (IF a condition THEN ... ELSE ...), and ITERATION (WHILE or FOR loops that repeat). A flowchart shows the same logic as a diagram. An oval marks START and END, a parallelogram is an input or output operation, a rectangle is a process step, a diamond is a decision with Yes/No branches, and arrows show the direction of flow. Why design before coding? Because a flowchart or pseudocode can be checked, shared with teammates, and fixed cheaply on paper. Fixing a flawed plan after writing hundreds of lines of code costs far more time and effort. Stuck? Start by writing the very first concrete step in plain words, then ask 'what happens next?' until you reach the end.