整理了一下使用資料結構這本書上的內容

順序棧類 sq_Stack.h

#pragma once
#include<iostream>
using namespace std;
template<class T>
class sq_Stack {
private:
	int mm;
	int top;
	T*s;
public:
	sq_Stack(int);//建構函式
	~sq_Stack();//解構函式
	void prt_sq_Stack();//順序輸出棧頂指標與棧中元素
	int flag_sq_Stack();//檢測順序棧狀態
	void ins_sq_Stack(T);//入棧
	T del_sq_Stack();//退棧
	T read_sq_Stack();//讀取棧頂元素
};
//建立容量為mm的空棧 
template<class T>
sq_Stack<T>::sq_Stack(int m)
{
	mm = m;
	s = new T[mm];
	top = 0;
	return;
}
//解構函式
template<class T >
sq_Stack<T>::~sq_Stack()
{
	delete[]s;
	top = 0;
	mm = 0;
	return;
}
//順序輸出棧頂指標與棧中元素
template<class T>
void sq_Stack<T>::prt_sq_Stack()
{
	cout << "top=" << top << endl;
	for (int i = top - 1; i >= 0; i--)
	{
		cout << s[i] << " ";
	}
	return;
}
//檢測順序棧狀態
template<class T>
int sq_Stack<T>::flag_sq_Stack()
{
	if (top == mm)return -1;//滿棧
	if (top == 0)return 0;//空棧
	return 1;
}
//入棧
template<class T>
void sq_Stack<T>::ins_sq_Stack(T data)
{
	if (top == mm)
	{
		cout << "overflow"; return;
	}
	s[top] = data;
	top++;
	return;
}
//退棧
template<class T>
T sq_Stack<T>::del_sq_Stack()
{
	if (top == 0)
	{
		cout << "underflow";
		return(0);
	}
	top--;
	return s[top];
}
//讀取棧頂元素
template<class T>
T sq_Stack<T>::read_sq_Stack()
{
	if (top == 0)
	{
		cout << "empty";
		return(0);
	}
	return s[top - 1];
}
//int main()
//{
//	sq_Stack<int> s(10);
//	s.ins_sq_Stack(50); s.ins_sq_Stack(60); s.ins_sq_Stack(70); s.ins_sq_Stack(80); s.ins_sq_Stack(90); s.ins_sq_Stack(100);
//	s.prt_sq_Stack();
//	cout << endl;
//	cout << s.read_sq_Stack();
//	cout << endl;
//	cout << s.del_sq_Stack();
//	cout << s.del_sq_Stack();
//	cout << s.del_sq_Stack();
//	cout << endl;
//	s.prt_sq_Stack();
//}
 

利用棧來實現表示式

#include"sq_Stack.h"
double shishu(char*s, int *k)
{
	double  x = 0.0, y = 1.0;
	int flag = 1;
	char c;
	c = s[*k];
	while (c >= '0'&&c <= '9' || c == '.')
	{
		*k = *k + 1;
		if (c >= '0'&&c <= '9')
		{
			if (flag == 0)//處理小數點以後的資料
			{
				y *= 0.1; x += (c - '0')*y;
			}
			else//處理小數點之前的資料
			{
				x *= 10; x += c - '0';

			}
		}
		else
			flag = 0;
		c = s[*k];
	}
	return x;
}
//計算運算子的優先順序
int pp(char c)
{
	int k;
	switch (c)
	{
	case'*':k = 2; break;
	case'/':k = 2; break;
	case'+':k = 1; break;
	case'-':k = 1; break;
	case'(':k = 0; break;
	case')':k = 0; break;
	case 0:k = -1; break;
	}
	return k;
}
int main()
{
	sq_Stack<double> sv(50);
	sq_Stack<char> sp(20);
	char s[60], c;
	int flag = 1, k;
	double x, y;
	sp.ins_sq_Stack(0);//表示式結束符進運算子棧
	cout << "input s:" << endl;
	cin >> s;
	k = 0;//掃描指標初始化
	c = s[k];
	while (flag)
	{
		if (c >= '0'&&c <= '9' || c == '.')//當前字元為數字字元或小數點
			sv.ins_sq_Stack(shishu(s, &k));
		else if (c == '(' || pp(c) > pp(sp.read_sq_Stack()))
		{
			sp.ins_sq_Stack(c);
			k++;
		}
		else if (c == 0&&sp.read_sq_Stack() == 0)
			flag = 0;
		else if (c == ')' && (sp.read_sq_Stack() == '('))
		{
			sp.del_sq_Stack();
			k++;
		}
		else if (pp(c) <=pp(sp.read_sq_Stack()))
		{
			y = sv.del_sq_Stack();
			x = sv.del_sq_Stack();
			c = sp.del_sq_Stack();
			switch (c)
			{
			case'*':x = x*y; break;
			case'/':x = x / y; break;
			case'+':x = x + y; break;
			case'-':x = x - y; break;
			}
			sv.ins_sq_Stack(x);
		}
		c = s[k];
	}
	cout << s << "=" << sv.read_sq_Stack() << endl;
}