public static Term Multiply(Term a, Term b)
{
List <Multiplier> multipliers = new List <Multiplier>(a.multipliers);
foreach (Multiplier mul_b in b.multipliers)
{
int index = multipliers.FindIndex(delegate(Multiplier item){ return(item.name == mul_b.name); });
if (index == -1)
{
multipliers.Add(mul_b);
}
else
{
Multiplier mul_a = multipliers[index];
mul_a.power += mul_b.power;
multipliers[index] = mul_a;
}
}
return(new Term(a.count * b.count, multipliers, a.dimension + b.dimension));
}
public static Term Parse(string s)
{
int sign = 1;
List <Multiplier> multipliers = new List <Multiplier>();
string dimension = "";
int i = 0;
while (i < s.Length)
{
char c = s[i];
if (c == '-')
{
sign = -1;
}
else
{
bool is_dimension = (c == 'x' || c == 'y' || c == 'z');
if (is_dimension)
{
dimension = s.Substring(i, s.Length - i);
break;
}
else
{
Multiplier multiplier = new Multiplier();
multiplier.power = 1;
multiplier.name = c.ToString();
multipliers.Add(multiplier);
}
}
++i;
}
return(new Term(sign, multipliers, dimension));
}
