add gcd if all int

src/solver.c

@@ -32,6 +32,36 @@ static double positiv_zero(double num)
     return num;
 }
 
+int has_decimal_part(double num)
+{
+    return (num != (int)num);
+}
+
+int any_has_decimal_part(double *num, size_t len)
+{
+    while (len > 0)
+    {
+        if (has_decimal_part(num[len - 1]))
+            return 1;
+        len--;
+    }
+    return 0;
+}
+
+// find GCD of two integers using euclidean algorithm
+static int gcd_int(int a, int b)
+{
+    int tmp;
+
+    while (b != 0)
+    {
+        tmp = b;
+        b = a % b;
+        a = tmp;
+    }
+    return abs(a);
+}
+
 static void solve_degree_1(s_solution_degree_1 *solution, double a, double b)
 {
     solution->a = a;
@@ -44,6 +74,7 @@ static void solve_degree_2(s_solution_degree_2 *solution, double a, double b, do
 {
     double delta;
     double delta_sqrt;
+    int gcd;
 
     solution->a = a;
     solution->b = b;
@@ -56,11 +87,37 @@ static void solve_degree_2(s_solution_degree_2 *solution, double a, double b, do
     solution->delta_sqrt = ft_sqrt(solution->delta_absolute); // √|Δ|
     delta_sqrt = solution->delta_sqrt;
 
-    // terms
-    if (b)
-        solution->first_term = positiv_zero(-b / (2 * a)); // -b / 2a
-    if (delta)
-        solution->second_term = positiv_zero(delta_sqrt / 2 * a); // √|Δ| / 2a
+    /**
+     * SOLVE LEFT AND RIGHT TERMS AS DOUBLES
+     */
+
+    if (b != 0.0)
+        solution->left_term = positiv_zero(-b / (2 * a)); // -b / 2a
+    if (delta != 0.0)
+        solution->right_term = positiv_zero(delta_sqrt / 2 * a); // √|Δ| / 2a
+
+    /**
+     * COMPLEX : SOLVE TERMS AS FRACTIONS
+     */
+
+    // check
+    if (solution->delta_sign != DELTA_MINUS)
+        return;
+    if (any_has_decimal_part((double[]){b, a, solution->delta_sqrt}, 3))
+        return;
+    solution->all_int = true;
+
+    // right term
+    gcd = gcd_int((int)solution->delta_sqrt, (int)(a * 2));
+    solution->right_term_numerator = solution->delta_sqrt / gcd;
+    solution->right_term_denominator = (a * 2) / gcd;
+
+    // left term
+    if (b == 0.0)
+        return;
+    gcd = gcd_int((int)b, (int)(a * 2));
+    solution->left_term_numerator = -b / gcd;
+    solution->left_term_denominator = (a * 2) / gcd;
 }
 
 void solve(const s_polynom *polynom, s_solution *solution)