/// <summary>
/// 将计算数相加，与其他计算式的相加值一样时舍去
/// </summary>
/// <returns></returns>
private int[] IsCommon()
{
string s = "";
LinkBinaryTree <Number> ic = new LinkBinaryTree <Number>();
int[] c = ic.Arithmetic(a[0], a[1], '+', ref s);
c = ic.Arithmetic(c, a[2], '+', ref s);
c = ic.Arithmetic(c, a[3], '+', ref s);
return(c);
}
/// <summary>
/// 生成一个题目并保存至exercises.txt
/// </summary>
/// <param name="r">运算数范围</param>
/// <returns></returns>
public string GetProblem(int r, ref int[] result, ref int [] ic)
{
a = new int[4][] { new int[] { 0, 1 }, new int[] { 0, 1 }, new int[] { 0, 1 }, new int[] { 0, 1 } };
X = new char[3] {
' ', ' ', ' '
}; //默认为空格，方便判断
//至多有两对括号，且成对出现
//bool b1 = false, b2 = false;
//计算式至少有两个运算数，一个运算符，则a，d不为0
string problem = "";
//Random rd = new Random(Guid.NewGuid().GetHashCode());
//int i1 = rd.Next(0, 2);
//if(i1==1)
//{
// b1 = true;
// problem += "(";
//}
while (a[0][0] == 0)
{
GetNumber(a[0], r, ref problem);
}
GetSymbol(a[0][0], ref problem, ref X[0]);
GetNumber(a[1], r, ref problem);
GetSymbol(a[1][0], ref problem, ref X[1]);
GetNumber(a[2], r, ref problem);
GetSymbol(a[2][0], ref problem, ref X[2]);
while (a[3][0] == 0)
{
GetNumber(a[3], r, ref problem);
}
problem += "=";
ic = IsCommon();
//Console.WriteLine(problem);
TreeNode <Number> sym = new TreeNode <Number>();
GetTree(0, 3, sym);
LinkBinaryTree <Number> link = new LinkBinaryTree <Number>(sym.Data);
result = link.GetResult(sym, ref problem);
return(problem);
}