tasks a-s

Task/Pythagorean-triples/MATLAB/pythagorean-triples.m

@@ -0,0 +1,16 @@
+N=  100;
+  a = 1:N;
+  b = a(ones(N,1),:).^2;
+  b = b+b';
+  b = sqrt(b);  [y,x]=find(b==fix(b)); % test
+  % here some alternative tests
+  % b = b.^(1/k); [y,x]=find(b==fix(b)); % test 2
+  % [y,x]=find(b==(fix(b.^(1/k)).^k));  % test 3
+  % b=b.^(1/k); [y,x]=find(abs(b - round(b)) <= 4*eps*b);
+
+  z  = sqrt(x.^2+y.^2);
+  ix = (z+x+y<100) & (x < y) & (y < z);
+  p  = find(gcd(x(ix),y(ix))==1); 	% find primitive triples
+
+  printf('There are %i Pythagorean Triples and %i primitive triples with a perimeter smaller than %i.\n',...
+         sum(ix), length(p), N);