Fix Project Euler problem 3

Author: MaximSmolskiy

project-euler/Problem3/isPrime.m

@@ -1,17 +1,17 @@
 % pfz: returns the prime factorization of that number.
 % assumes: number is positive
-% uses: function isPrime
 function y = pfz(number)
   assert(number >= 0,'number must be positive')
   y = []; % collects all prime factors
-  tmp = number; % saves temporary the argument
-  for divisor = 2 : 1 : sqrt(number)
-    if (isPrime(divisor))
-      while (mod(number,divisor) == 0)
-        y = [y divisor];
-        number = idivide(number,divisor); % integer division
-      endwhile
-      number = tmp;
-    endif
-  endfor
+  divisor = 2;
+  while (divisor <= sqrt(number))
+    while (mod(number,divisor) == 0)
+      y = [y divisor];
+      number /= divisor; % integer division
+    endwhile
+    divisor += 1;
+  endwhile
+  if (number > 1)
+    y = [y number];
+  endif
 endfunction