/// <summary>第一次用开方尝试</summary>
private static List <int> FirstTry(List <int> result, List <int> div)
{
int tryDiv = BigNumber.Max / 2;
int low = 1;
int top = BigNumber.Max - 1;
//第一位数是1
//第一用平方试商
while (true)
{
if (BigCalculate.CompareList(new List <int>()
{
1
}, div) == 0)
{
div = BigCalculate.IntMinus(div, new List <int>()
{
1
});
result.Add(1);
break;
}
//连9都小了，那么就是9
if (BigCalculate.CompareList(BigCalculate.Multiply(BigNumber.Max - 1, BigNumber.Max - 1), div) == -1)
{
div = BigCalculate.IntMinus(div, BigCalculate.Multiply(BigNumber.Max - 1, BigNumber.Max - 1));
result.Add(BigNumber.Max - 1);
break;
}
int c = BigCalculate.CompareList(BigCalculate.Multiply(tryDiv, tryDiv), div);
//商大了
if (c == -1)
{
low = tryDiv;
tryDiv = (low + top) / 2;
}
else if (c == 1) //商小了
{
top = tryDiv;
tryDiv = (low + top) / 2;
}
else //刚好相等
{
div.Clear();
result.Add(tryDiv);
break;
}
if (low + 1 == top)
{
div = BigCalculate.IntMinus(div, BigCalculate.Multiply(low, low));
result.Add(low);
break;
}
}
return(div);
}
/// <summary>执行一次试商的运算</summary>
/// <param name="div">已经加组的被除数</param>
/// <param name="result">已生成的结果</param>
static List <int> TryDiv(List <int> div, List <int> result)
{
int i = BigNumber.Max / 2;
int low = 0;
int top = BigNumber.Max - 1;
//连1都大了,那么商为0，除数不变
if (CompartDiv(1, result, div) == 1)
{
result.Add(0);
return(div);
}
//连9999都小了
if (CompartDiv(BigNumber.Max - 1, result, div) == -1)
{
List <int> r = BigCalculate.IntMinus(div, CalDiv(BigNumber.Max - 1, result));
result.Add(BigNumber.Max - 1);
return(r);
}
while (true)
{
int c = CompartDiv(i, result, div);
//商大了
if (c == 1)
{
top = i;
i = (low + top) / 2;
}
//商小了
else if (c == -1)
{
low = i;
i = (low + top) / 2;
}
//刚好相等
else
{
//div.Clear();
result.Add(i);
return(new List <int>());
}
//已找到合适的商
if (low + 1 == top)
{
List <int> r = BigCalculate.IntMinus(div, CalDiv(low, result));
result.Add(low);
return(r);
}
}
}