[C++知识库]括号匹配——栈实现

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1.直接使用库函数stack

#include<iostream>
#include<string>
#include<cstring>
#include<cstdlib> 
#include<stack>
using namespace std;
#define MAXSIZE 20
void Matching(string s);
int main()
{
	int n = 0;
	cin >> n;
	while (n > 0)
	{
		string s;
		cin >> s;
		Matching(s);
		n--;
	}
	return 0;
}
void Matching(string s)
{
	stack<char>st;
	bool flag = 1;
	unsigned int i = 0;
	while (flag&&i < s.length())
	{
		switch (s[i])
		{
		case '(':
			st.push(s[i]);
			break;
		case '[':
			st.push(s[i]);
			break;
		case '{':
			st.push(s[i]);
			break;
		case ')':
			if (!st.empty() )
			{
				char ch=st.top();
				if(ch=='(')
				st.pop();
			}
			else flag = 0;
			break;
		case ']':
			if (!st.empty() )
			{
				char ch=st.top();
				if(ch=='[')
				st.pop();
			}
			else flag = 0;
			break;
		case '}':
			if (!st.empty() )
			{
				char ch=st.top();
				if(ch=='{')
				st.pop();
			}
			else flag = 0;
			break;
		}
		i++;
	}
	if (st.empty() && flag)
	{
		cout << "Yes\n";
	}
	else { cout << "No\n"; }
}

2.自定义栈的数据结构

#include<iostream>//内存超限 
#include<string>
#include<cstring> 
#include<cstdlib> 
#include<cstdio>
using namespace std;
#define MAXSIZE 20
typedef struct
{
	char *base;
	char *top;
	int stacksize;
}SqStack;
void InitStack(SqStack &S);
void Push(SqStack&S, char e);
void Pop(SqStack&S, char &e);
char GetTop(SqStack S);
bool StackEmpty(SqStack S);
void Matching(string s);
int main()
{
	int n = 0;
	cin >> n;
	while (n > 0)
	{
		string s;
		cin >> s;
		Matching(s);
		n--;
	}
	return 0;
}
void Matching(string s)
{
	SqStack S;
	InitStack(S);
	bool flag = 1;
	unsigned int i = 0;
	while (flag&&i < s.length())
	{
		switch (s[i])
		{
		case '(':
			Push(S, s[i]);
			break;
		case '[':
			Push(S, s[i]);
			break;
		case '{':
			Push(S, s[i]);
			break;
		case ')':
			if (!StackEmpty(S) && GetTop(S) == '(')
			{
				Pop(S, s[i]);
			}
			else flag = 0;
			break;
		case ']':
			if (!StackEmpty(S) && GetTop(S) == '[')
			{
				Pop(S, s[i]);
			}
			else flag = 0;
			break;
		case '}':
			if (!StackEmpty(S) && GetTop(S) == '{')
			{
				Pop(S, s[i]);
			}
			else flag = 0;
			break;
		}
		i++;
	}
	if (StackEmpty(S) && flag)
	{
		cout << "Yes\n";
	}
	else { cout << "No\n"; }
}
void InitStack(SqStack &S)
{
	S.base = new char[MAXSIZE];
	S.top = S.base;
	S.stacksize = MAXSIZE;
} 
void Push(SqStack&S, char e)
{
	if (S.top - S.base == S.stacksize)return;
	*S.top++ = e;
}
void Pop(SqStack&S, char &e)
{
	if (S.top == S.base)return;
	e = *--S.top;
}
char GetTop(SqStack S)
{
	if (S.top != S.base)
		return *(S.top - 1);
	return -1;
}
bool StackEmpty(SqStack S)
{
	if (S.top == S.base)
		return true;
	return false;
}