新建 文本文档.txt

本程序为用VC开发的词法分析程序

int CMyDialog::stringtoint(CString str_in)
{
	int result;
	if(str_in.GetAt(0)=='+'||'-')
	{
		char ch;
		for(int i=1;i<str_in.GetLength()+1;i++)
		{
			ch=str_in.GetAt(i);
			switch(ch)
			{
				case '0':
					result=result+0*ten(i);
					break;
				case '1':
					result=result+1*ten(i);
					break;
				case '2':
					result=result+2*ten(i);
					break;
				case '3':
					result=result+3*ten(i);
					break;
				case '4':
					result=result+4*ten(i);
					break;
				case '5':
					result=result+5*ten(i);
					break;
				case '6':
					result=result+6*ten(i);
					break;
				case '7':
					result=result+7*ten(i);
					break;
				case '8':
					result=result+8*ten(i);
					break;
				case '9':
					result=result+9*ten(i);
					break;
			}
		}
	}
	else
	{
		char ch;
		for(int i=0;i<str_in.GetLength()+1;i++)
		{
			ch=str_in.GetAt(i);
			switch(ch)
			{
				case '0':
					result=result+0*ten(i);
					break;
				case '1':
					result=result+1*ten(i);
					break;
				case '2':
					result=result+2*ten(i);
					break;
				case '3':
					result=result+3*ten(i);
					break;
				case '4':
					result=result+4*ten(i);
					break;
				case '5':
					result=result+5*ten(i);
					break;
				case '6':
					result=result+6*ten(i);
					break;
				case '7':
					result=result+7*ten(i);
					break;
				case '8':
					result=result+8*ten(i);
					break;
				case '9':
					result=result+9*ten(i);
					break;
			}
		}
	}
	return result;
}

int CMyDialog::ten(int in)
{
	switch(in)
	{
		case 0:
			return 0;
		case 1:
			return 1;
		case 2:
			return 10;
		case 3:
			return 100;
		case 4:
			return 1000;
		case 5:
			return 10000;
		default:
			return 0;
	}
}