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Classic Algorithms in Befunge
How familiar algorithms such as factorials, GCD and sorting change shape when the only tools are a stack, a movable pointer and a small grid of cells.
Programming in Funge
Algorithms in Funge
Classic algorithms worked through on a grid.
Computing Factorials on a Grid
Build a small Befunge factorial program with a loop, a scratch cell and a pass-by-pass table showing the stack and accumulator at every step.
Converting Numbers Between Bases
Convert a number to binary in Befunge by repeated division, then fix the backward digit order by letting the stack hand the digits back in reverse.
Euclids Method for Greatest Common Divisors
Turn the remainder-based Euclidean algorithm into a tested Befunge program, with pointer paths, stack contents and a scratch cell for the missing rotation.
Generating Fibonacci Numbers in a Grid Language
A tested Befunge program prints Fibonacci numbers using dup, swap and a scratch cell in place of rotation, with the stack traced pass by pass.
Random Choice with the Question Mark Instruction
How the Befunge question mark sends the pointer in a random direction, with a tested coin-flip program and ways to make programs tolerate chance.
Reversing a String with the Stack
Read characters until a newline, push them on the Befunge stack, then pop and print them backward, using the stack's own ordering to do the reversal.
Sorting Small Lists in a Grid Language
Without arrays, a Befunge sort stores values in grid cells and compares them pair by pair. See a tested compare-and-order routine and what a full sort costs.
Testing for Primes by Trial Division
A tested Befunge program checks whether a number is prime by trying each divisor in turn, and the article explains its limits in such a small language.
Writing a Quine in a Grid Language
A 14-cell Befunge quine reads its own cells with get and prints them, showing how the playfield doubles as data. Includes a cell-by-cell explanation.
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