picat/fib.pi


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18

main =>
S = 0,
    I = 1,
    F = fib(I),
    while (F <= 4000000)
        if (F mod 2 == 0) then
            S := S+F
        end,
        I := I+1,
        F := fib(I)
    end,
    printf("Sum of the even-valued terms is %w%n",S).
main([A1]) =>
    printf("fib(%s)=%w%n",A1,A1.to_integer().fib()).
table
fib(1) = 1.
fib(2) = 2.
fib(N) = fib(N-1)+fib(N-2).