public static BigInt operator +(BigInt fst, BigInt snd)
{
fst.Trim(); snd.Trim();
if (fst.IsNegative && snd.IsNegative)
{
return(-(fst.Abs() + snd.Abs()));
}
if (fst.IsNegative && !snd.IsNegative)
{
return(snd.Abs() - fst.Abs());
}
if (!fst.IsNegative && snd.IsNegative)
{
return(fst.Abs() - snd.Abs());
}
int bound = CommonBound(fst, snd) + 1;
var res = new BigInt(0);
bool carry = false;
foreach (var i in 0.to(bound))
{
int addition = NumberUtil.CountTrue(carry, fst[i], snd[i]);
switch (addition)
{
case 0:
res[i] = false; carry = false; break;
case 1:
res[i] = true; carry = false; break;
case 2:
res[i] = false; carry = true; break;
case 3:
res[i] = true; carry = true; break;
default: break;
}
}
res.Trim();
return(res);
}
