//Stack.h
#ifndef STACK_H
#define STACK_H
#include<iostream>
class stack_int
{
private:
 int* bottom;   //棧底
 int* top;    //棧頂
 unsigned int capacity;//棧容量
 unsigned int size; //棧大小
public:
 stack_int() :bottom(new int[11]), top(bottom), capacity(10), size(0) {};
 stack_int(unsigned int capacity) :bottom(new int[capacity+1]),top(bottom), capacity(capacity),size(0){};
 int operator[](unsigned int i) const
 {
 return *(bottom + i);
 }
 bool isEmpty()const { return bottom == top; }
 bool isFull()const { return size == capacity-1; }
 unsigned int getsize()const { return size; }
 unsigned int getcapacity()const { return capacity; }
 int gettop()const
 {
 if (!isEmpty())
 return *(top - 1);
 else
 return -1;
 }
 void settop(int i)
 {
 if (!isEmpty())
 {
 *(top - 1) = i;
 }
 }
 void push(int i)
 {
 if ((top - bottom)<capacity)
 {
 *top = i;
 top++;
 size++;
 }
 else
 {
 std::cout << "stack full!" << std::endl;
 stack_expansion();
 push(i);
 }
 }
 int pop(int &val)
 {//返回值為1則棧未空，返回值為0則棧已空無法出棧
 if (top > bottom)
 {
 top--;
 size--;
 val = *top;
 return 1;
 }
 else
 {
 std::cout << "stack empty!" << std::endl;
 return NULL;
 }
 }
private:
 void stack_expansion()
 {//棧擴容
 std::cout << "正在擴容中..." << std::endl;
 int newcapacity = 2 * capacity + 1;
 int* newbottom = new int[newcapacity + 1];
 int* newtop = newbottom;
 for (int i = 0; i < size; ++i)
 {
 *newtop = *bottom;
 newtop++;
 bottom++;
 }
 bottom = newbottom;
 top = newtop;
 capacity = newcapacity;
 }
};
#endif

//Main.cpp
#include"stack.h"
#include<iostream>
using namespace std;
bool is_digit(char i)
{//是數(shù)字
 if (i == '1' || i == '2' || i == '3' || i == '4' || i == '5' || i == '6' || i == '7' || i == '8' || i == '9' || i == '0')
 return true;
 else return false;
}
bool is_operator(char i)
{//是運算符
 if (i == '+' || i == '-' || i == '*' || i == '/' ||i=='=')
 return true;
 else return false;
}
bool get_priority(char pre,char cur)
{//獲取兩個符號間的優(yōu)先級,pre為靠前的字符，cur為靠后的字符
 if ((pre == '+' || pre == '-') && (cur == '*' || cur == '/'))
 return false;
 else
 return true;
}
int do_operation(int lnum, char ope, int rnum)
{
 if (ope == '+')
 return lnum + rnum;
 if (ope == '-')
 return lnum - rnum;
 if (ope == '*')
 return lnum * rnum;
 if (ope == '/')
 return lnum / rnum;
}
/*
1+2*3=
1+5*4-345+36/6*4+145*4*5-52=
*/

int main()
{
 stack_int s;
 stack_int num_stack;//數(shù)據(jù)棧
 stack_int ope_stack;//符號棧
 char current_char;
 current_char = getchar();
 bool overflag = false;
 while (overflag!=true)
 {//未遇到=號時不斷進行四則運算
 if (is_digit(current_char))
 {//遇到數(shù)字符號則將完整的數(shù)解析出來并保存于棧中
 int num = 0;
 num = current_char - '0';//符號轉(zhuǎn)數(shù)字
 current_char = getchar();//獲取下一個字符
 while (is_digit(current_char))
 {
 num = num * 10+(current_char-'0');
 current_char = getchar();
 }
 num_stack.push(num);
 //cout <<"the number is " <<num << endl;
 }
 if (current_char == ' ')
 {//空格則繼續(xù)
 current_char = getchar();
 continue;
 }
 if (is_operator(current_char))
 {//遇到運算符則將運算符保存于運算符棧中
 int ope = '?';
 //如果當(dāng)前符號棧非空，則不斷根據(jù)優(yōu)先級決定是否進行一次運算
 while((!ope_stack.isEmpty())&&(get_priority((char)ope_stack.gettop(),current_char)))
 {//如果前一個運算符優(yōu)先級更高
 ope_stack.pop(ope);
 //cout << "找到了前一個運算符為: " << (char)ope << endl;
 int lnum, rnum;
 //符號棧非空時，數(shù)據(jù)棧應(yīng)該至少有兩個數(shù)，否則出錯
 if (num_stack.isEmpty())
 {
  cout << "數(shù)據(jù)棧缺失兩個元素，解析失??！" << endl;
  overflag = true;
  break;
 }
 num_stack.pop(rnum);
 if (num_stack.isEmpty())
 {
  cout << "數(shù)據(jù)棧缺失一個元素，解析失??！" << endl;
  overflag = true;
  break;
 }
 num_stack.pop(lnum);
 lnum = do_operation(lnum, (char)ope, rnum);//進行運算
 num_stack.push(lnum); 
 }
 if (current_char == '=')
 {//如果解析到=號了,解析完成
 overflag = true;
 break;
 }
 ope_stack.push(current_char);
 current_char = getchar();
 }
 }
 for (int i = 0; i < num_stack.getsize(); ++i)
 cout << num_stack[i] << "\t";
 cout << endl;
 for (int i = 0; i < ope_stack.getsize(); ++i)
 cout << (char)ope_stack[i] << "\t";
 return 0;
}

if (is_operator(current_char))

while((!ope_stack.isEmpty())&&(get_priority((char)ope_stack.gettop(),current_char)))