fix null coefficient skipped

src/parser.c

@@ -208,7 +208,7 @@ void parse(s_token *tokens, s_term *terms, int terms_count_max)
 
     check_variables(tokens);
 
-    print_debug("PARSER STEPS :\n"); // debug
+    print_debug("PARSER STEPS :\n");
 
     terms_count = 0;
     token_count = 0;
@@ -216,7 +216,7 @@ void parse(s_token *tokens, s_term *terms, int terms_count_max)
     term_position = TERM_LEFT;
     while (tokens[i].type != TOKEN_END && terms_count < terms_count_max)
     {
-        print_debug("- token[%i]\n", i); // debug
+        print_debug("- token[%i]\n", i);
 
         // equal
         if (tokens[i].type == TOKEN_EQUAL)
@@ -238,19 +238,19 @@ void parse(s_token *tokens, s_term *terms, int terms_count_max)
             sign = -1;
         }
         i += token_count;
-        print_debug("term[%i] get_sign: (%i)[%s], token_count: [%d]\n", terms_count, ret_sign, term_sign_to_str(ret_sign), token_count); // debug
+        print_debug("term[%i] get_sign: (%i)[%s], token_count: [%d]\n", terms_count, ret_sign, term_sign_to_str(ret_sign), token_count);
 
         // coefficient
         double ret_coefficient = get_coefficient(tokens, i, &token_count);
         terms[terms_count].coefficient = ret_coefficient * sign;
         i += token_count;
-        print_debug("term[%i] get_coefficient: [%g], token_count: [%d]\n", terms_count, ret_coefficient, token_count); // debug
+        print_debug("term[%i] get_coefficient: [%g], token_count: [%d]\n", terms_count, ret_coefficient, token_count);
 
         // exponent
         int ret_exponent = get_exponent(tokens, i, &token_count);
         terms[terms_count].exponent = ret_exponent;
         i += token_count;
-        print_debug("term[%i] get_exponent: [%i], token_count: [%d]\n", terms_count, ret_exponent, token_count); // debug
+        print_debug("term[%i] get_exponent: [%i], token_count: [%d]\n", terms_count, ret_exponent, token_count);
 
         terms_count++;
     }

src/reducer.c

@@ -64,5 +64,10 @@ int reduce(s_term *terms, s_polynom *polynom, int max_exponent)
         i++;
     }
 
+    // fill END polynom
+    polynom[i].coefficient = 0.0;
+    polynom[i].exponent = 0;
+    polynom[i].sign = TERM_SIGN_END;
+
     return degree;
 }

src/solver.c

@@ -2,6 +2,29 @@
 
 #include "computorv1.h"
 
+static double get_coefficient_of_power(int power, const s_polynom *polynom)
+{
+    int i;
+    double coefficient;
+
+    // if no term found with exponent, default coefficient is 0
+    coefficient = 0;
+
+    i = 0;
+    while (polynom[i].sign != TERM_SIGN_END)
+    {
+        if (polynom[i].exponent == power)
+        {
+            coefficient = polynom[i].coefficient;
+            break;
+        }
+        i++;
+    }
+
+    print_debug("- coefficient of power '%i' : %g (polynom[%i])\n", power, coefficient, i);
+    return coefficient;
+}
+
 static double positiv_zero(double num)
 {
     if (num == 0)
@@ -48,16 +71,16 @@ void solve(const s_polynom *polynom, s_solution *solution)
 
     if (solution->degree == 1)
     {
-        a = polynom[0].coefficient;
+        a = get_coefficient_of_power(1, polynom);
-        b = polynom[1].coefficient;
+        b = get_coefficient_of_power(0, polynom);
 
         solve_degree_1(&solution->solution_degree_1, a, b);
     }
     else if (solution->degree == 2)
     {
-        a = polynom[0].coefficient;
+        a = get_coefficient_of_power(2, polynom);
-        b = polynom[1].coefficient;
+        b = get_coefficient_of_power(1, polynom);
-        c = polynom[2].coefficient;
+        c = get_coefficient_of_power(0, polynom);
 
         solve_degree_2(&solution->solution_degree_2, a, b, c);
     }