输入一串字符，分别输出字母 数字 符号的个数，以$结束

# include <iostream>

using namespace std;

int main()
{
	char ch;
	int xiao = 0;
	int da = 0;
	int num = 0;
	int space = 0;
	int qi = 0;

	cout << "请输入一串字符，以$结束：\n";

	while((ch = getchar()) != '$')
	{
		if(ch >= 'a' && ch <= 'z')
		{
			++xiao;
		}

		else if(ch >= 'A' && ch <= 'Z')
		{
			++da;
		}

		else if(ch >= 48 && ch <= 57)
		{
			++num;
		}

		else if(ch == ' ')
		{
			++space;
		}

		else
		{
			++qi;
		}
	}

	cout << "小写字母："
		 << xiao
		 << endl
		 << "大写字母："
		 << da
		 << endl
		 << "数字："
		 << num
		 << endl
		 << "空格："
		 << space
		 << endl
		 << "其他字符："
		 << qi
		 << endl;

	return 0;
}