| caryclark@google.com | 27accef | 2012-01-25 18:57:23 +0000 | [diff] [blame] | 1 | #include "QuadraticUtilities.h" |
| caryclark@google.com | d88e089 | 2012-03-27 13:23:51 +0000 | [diff] [blame^] | 2 | #include <math.h> |
| caryclark@google.com | 27accef | 2012-01-25 18:57:23 +0000 | [diff] [blame] | 3 | |
| 4 | int quadraticRoots(double A, double B, double C, double t[2]) { |
| 5 | B *= 2; |
| 6 | double square = B * B - 4 * A * C; |
| 7 | if (square < 0) { |
| 8 | return 0; |
| 9 | } |
| 10 | double squareRt = sqrt(square); |
| 11 | double Q = (B + (B < 0 ? -squareRt : squareRt)) / -2; |
| 12 | int foundRoots = 0; |
| 13 | if ((Q <= A) ^ (Q < 0)) { |
| 14 | t[foundRoots++] = Q / A; |
| 15 | } |
| 16 | if ((C <= Q) ^ (C < 0)) { |
| 17 | t[foundRoots++] = C / Q; |
| 18 | } |
| 19 | return foundRoots; |
| 20 | } |
| 21 | |
| 22 | |