/*
 * hanoi.t - standard "Towers of Hanoi" in toy.
 */

proc printPeg(int peg)void:

    if peg = 1 then
        write("left");
    elif peg = 2 then
        write("center");
    else
        write("right");
    fi;
corp;

proc hanoi(int n, fromPeg, usingPeg, toPeg)void:

    if n ~= 0 then
        hanoi(n - 1, fromPeg, toPeg, usingPeg);
        write("Move disk from ");
        printPeg(fromPeg);
        write(" peg to ");
        printPeg(toPeg);
        write(" peg.\n");
        hanoi(n - 1, usingPeg, fromPeg, toPeg);
    fi;
corp;

proc main()void:
    int n;

    write("How many pegs? ");
    readln(n);
    hanoi(n, 1, 2, 3);
corp;