Problem 11 - Io

After writing up a somewhat full solution to Problem 93 in Io, I found out that that solution was far, far too slow to run. Thus, I looked for a much, much simpler problem that I could solve in Io in order to free up another language for 93. Problem 11 was a good choice, as the problem is quite simple, other than requiring working with a 2-dimensional array, which is very doable in Io. So, I replaced my old PHP solution from a long time ago with an Io solution. This was mostly an easy matter of translating, nothing special. Solution runs in about 0.1s on my machine (for what it's worth, my PHP solution runs in about 1/5 of the time, and of course that is worth very little on these time scales).

matrix := list(list( 8, 2,22,97,38,15, 0,40, 0,75, 4, 5, 7,78,52,12,50,77,91, 8),
    list(49,49,99,40,17,81,18,57,60,87,17,40,98,43,69,48, 4,56,62, 0),
    list(81,49,31,73,55,79,14,29,93,71,40,67,53,88,30, 3,49,13,36,65),
    list(52,70,95,23, 4,60,11,42,69,24,68,56, 1,32,56,71,37, 2,36,91),
    list(22,31,16,71,51,67,63,89,41,92,36,54,22,40,40,28,66,33,13,80),
    list(24,47,32,60,99, 3,45, 2,44,75,33,53,78,36,84,20,35,17,12,50),
    list(32,98,81,28,64,23,67,10,26,38,40,67,59,54,70,66,18,38,64,70),
    list(67,26,20,68, 2,62,12,20,95,63,94,39,63, 8,40,91,66,49,94,21),
    list(24,55,58, 5,66,73,99,26,97,17,78,78,96,83,14,88,34,89,63,72),
    list(21,36,23, 9,75, 0,76,44,20,45,35,14, 0,61,33,97,34,31,33,95),
    list(78,17,53,28,22,75,31,67,15,94, 3,80, 4,62,16,14, 9,53,56,92),
    list(16,39, 5,42,96,35,31,47,55,58,88,24, 0,17,54,24,36,29,85,57),
    list(86,56, 0,48,35,71,89, 7, 5,44,44,37,44,60,21,58,51,54,17,58),
    list(19,80,81,68, 5,94,47,69,28,73,92,13,86,52,17,77, 4,89,55,40),
    list( 4,52, 8,83,97,35,99,16, 7,97,57,32,16,26,26,79,33,27,98,66),
    list(88,36,68,87,57,62,20,72, 3,46,33,67,46,55,12,32,63,93,53,69),
    list( 4,42,16,73,38,25,39,11,24,94,72,18, 8,46,29,32,40,62,76,36),
    list(20,69,36,41,72,30,23,88,34,62,99,69,82,67,59,85,74, 4,36,16),
    list(20,73,35,29,78,31,90, 1,74,31,49,71,48,86,81,16,23,57, 5,54),
    list( 1,70,54,71,83,51,54,69,16,92,33,48,61,43,52, 1,89,19,67,48));

max := method(x, y, if(x > y, x, y))

maxProd := 0;
bound := matrix size;
for (i, 0, bound - 1,
    for (j, 0, bound - 1,
    (i + 3 < bound) ifTrue (maxProd := max((matrix at(i) at(j)) * 
    (matrix at(i+1) at(j)) * (matrix at(i+2) at (j)) * (matrix at(i+3) at(j)), maxProd));
    (j + 3 < bound) ifTrue (maxProd := max((matrix at(i) at(j)) * 
    (matrix at(i) at(j+1)) * (matrix at(i) at (j+2)) * (matrix at(i) at(j+3)), maxProd));
    (i + 3 < bound and j + 3 < bound) ifTrue (maxProd := max((matrix at(i) at(j)) * 
    (matrix at(i+1) at(j+1)) * (matrix at(i+2) at (j+2)) * (matrix at(i+3) at(j+3)), maxProd));
    (i + 3 < bound and j > 2) ifTrue (maxProd := max((matrix at(i) at(j)) * 
    (matrix at(i+1) at(j-1)) * (matrix at(i+2) at (j-2)) * (matrix at(i+3) at(j-3)), maxProd));                   
    )
)

maxProd print;