闲来无事，写个四则运算的计算式【包括+，-，*，/，没有括号】；

代码如下：

#include <iostream>
#include <stack>
#include <string>
using namespace std;
class Calc
{
public:
	int judge (const string &str)
	{
		if (str.find ('=') == string::npos)
		{
			cout<<"input error"<<endl;
			return -1;
		}
	}
	int process (int a, int b, char op)
	{
		if (op == '+')
		{
			return a + b;
		}
		if (op == '-')
		{
			return a - b;
		}
		if (op == '*')
		{
			return a * b;
		}
		return a/b;
	}
	int result (const string &str)
	{
		string::const_iterator data = http://www.mamicode.com/str.begin ();>
int main ()
{
	string data;
	Calc calc;
	while (cin>>data)
	{

		cout<<calc.result (data)<<endl;
	}
	return 0;
}


四则运算的实现