Updated bisection root finding algorithm and test case

tests/UPolynomialRootsTestCases.pas

@@ -54,15 +54,31 @@ begin
 end;
 
 procedure TPolynomialRootsTestCase.TestBisectionRootIsolation;
+const
+  expRoots: array of Cardinal = (34000, 23017, 5);
 var
+  exp: Cardinal;
   a: TBigIntPolynomial;
-  r: Int64;
+  r: TIsolatingIntervals;
+  ri: TIsolatingInterval;
+  found: Boolean;
 begin
   // y = 3 * (x - 34000) * (x - 23017) * (x - 5) * (x^2 - 19) * (x + 112)
   //   = 3 * x^6 - 170730 * x^5 + 2329429920 * x^4 + 251300082690 * x^3 - 1270471872603 * x^2 + 4774763204640 * x - 24979889760000
   a := TBigIntPolynomial.Create([-24979889760000, 4774763204640, -1270471872603, 251300082690, 2329429920, -170730, 3]);
   r := FRootIsolation.Bisect(a);
-  AssertEquals(0, r);
+  AssertEquals(Length(expRoots), r.Count);
+  for exp in expRoots do
+  begin
+    found := False;
+    for ri in r do
+      if (ri.A <= exp) and (exp <= ri.B) then
+      begin
+        found := True;
+        Break;
+      end;
+    AssertTrue('No isolating interval for expected root ' + IntToStr(exp) + ' found.', found);
+  end;
 end;
 
 initialization