支援大於十的整數，加減乘除小括號

#include <iostream>
#include <stack>

using namespace std;

stack<char> s_opt;//操作符棧
stack<int> s_num;//資料棧

int Priority(char ch){//判斷優先順序
	switch(ch){
		case '(':
			return 3;
		case '*':
		case '/':
			return 2;
		case '+':
		case '-':
			return 1;
		default:
			return 0;
	}
}

int main(){

	char opt[1024] = {0};
	int i = 0, tmp = 0, num1 = 0, num2 = 0;
	cout << "Please input: " << endl;
	cin >> opt;
	while(opt[i] != '\0' || s_opt.empty() != true){
        if(opt[i] >= '0' && opt[i] <= '9'){
            tmp = tmp * 10 + opt[i] - '0';
            i++;
            if(opt[i] > '9' || opt[i] < '0'){
                s_num.push(tmp);
                tmp = 0;

            }
        }
        else{
			if((opt[i] == ')') && (s_opt.top() == '(')){
				s_opt.pop();
				i++;
				continue;
			}

			if((s_opt.empty()) == true || (Priority(opt[i]) > Priority(s_opt.top()))||(s_opt.top() == '(' && (opt[i] != ')'))){
				s_opt.push( opt[i]);
				i++;
				continue;
			}

			if( ((opt[i] == '\0') &&( s_opt.empty() != true)) || ( (opt[i] == ')') && (s_opt.top() != '(') )||(Priority(opt[i]) <= Priority(s_opt.top()))	){
				char ch = s_opt.top();
				s_opt.pop();
				int num1,num2;
				switch(ch){
					case'+':
						num1 = s_num.top();
						s_num.pop();
						num2 = s_num.top();
						s_num.pop();
						s_num.push(num1 + num2);
						break;

					case'-':
						num1 = s_num.top();
						s_num.pop();
						num2 = s_num.top();
						s_num.pop();
						s_num.push(num2 - num1);//1 2
					break;
					case'*':
						num1 = s_num.top();
						s_num.pop();
						num2 = s_num.top();
						s_num.pop();
						s_num.push(num1 * num2);
					break;
					case'/':
						num1 = s_num.top();
						s_num.pop();
						num2 = s_num.top();
						s_num.pop();
						s_num.push(num1 / num2);
					break;
				}
			}
		}
	}

	cout << s_num.top() << endl;
	return 0;
}