Algorithm
Edit Watch this page Read in another language Algorithm For other uses, see Algorithm (disambiguation) . Flow chart of an algorithm ( Euclid's algorithm ) for calculating the greatest common divisor (g.c.d.) of two numbers a and b in locations named A and B. The algorithm proceeds by successive subtractions in two loops: IF the test B ≥ A yields "yes" (or true) (more accurately the number b in location B is greater than or equal to the number a in location A) THEN, the algorithm specifies B ← B − A (meaning the number b − a replaces the old b ). Similarly, IF A > B, THEN A ← A − B. The process terminates when (the contents of) B is 0, yielding the g.c.d. in A. (Algorithm derived from Scott 2009:13; symbols and drawing style from Tausworthe 1977). In mathematics and computer science , an algorithm ( / ˈ æ l ɡ ə r ɪ ð əm / ( listen ) AL -gə-ridh-əm ) is an unambiguous specification of how to solve a class of problems.