I have a mistake in loops

Hello, I have somewhere a mistake that if N = 1000 the output misses some lines (don't know which), so I suppose there's a mistake somewhere in for loops. It works correctly with N = 50, 100, 500.

function [R, I] = problem2B(N)
I = 0;
for a = 3:N
    for b = a:N
        for c = b:N
            if (a^2 + b^2) == c^2 && a+b+c < N
                R(I+1, :) = [a+b+c, a, b, c];
                I = I + 1;
            elseif N < 12
                R = zeros(4, 1);
            end
        end
    end
end
if N <= 50
    R = reshape(nonzeros(R), I, 4);
else
    R = sortrows(R, 1);
end
end

[DGM]

What exactly do you mean when you say it misses rows?

[R I] = problem2B(100)

R = 17×4

12 3 4 5 24 6 8 10 30 5 12 13 36 9 12 15 40 8 15 17 48 12 16 20 56 7 24 25 60 10 24 26 60 15 20 25 70 20 21 29

I = 17

[R I] = problem2B(1000)

R = 324×4

12 3 4 5 24 6 8 10 30 5 12 13 36 9 12 15 40 8 15 17 48 12 16 20 56 7 24 25 60 10 24 26 60 15 20 25 70 20 21 29

I = 324

function [R, I] = problem2B(N)
I = 0;
for a = 3:N
    for b = a:N
        for c = b:N
            if (a^2 + b^2) == c^2 && a+b+c < N
                R(I+1, :) = [a+b+c, a, b, c];
                I = I + 1;
            elseif N < 12
                R = zeros(4, 1);
            end
        end
    end
end

if N <= 50
    R = reshape(nonzeros(R), I, 4);
else
    R = sortrows(R, 1);
end
end

[sznailc]

I have a test file that says, that not all possible pythagorean triples are displayed with N = 1000. Therefore I think there has to be a mistake with indexes that it skips some possible triples.

[Stephen23]

Note that if you change to

R = zeros(0,4);

then you can get rid of NONZEROS and RESHAPE.

Answer 1

[Steven Lord]

Does your problem ask you to find all Pythagorean triples whose elements sum to less than 1000 or all whose elements sum to less than or equal to 1000?

[sznailc]

wow, thank you, edited to a+b+c <= N. I couldn't tell what triple is missing and didn't know that it might be 1000