栈的应用---括号匹配

思路：

从第一个字符开始扫描

当遇见普通字符时忽略

当遇见左符号时压入栈中

当遇见右符号时从栈中弹出栈顶符号，并进行匹配
           匹配成功:继续读入下一个字符
           匹配失败:立即停止，并报错结束:

成功:所有字符扫描完毕，且栈为空
失败:匹配失败或所有字符扫描完毕但栈非空 

Stack_Pare_Match.h

#include "Chain_Stack.h"

bool isLeft(char c);
bool isRight(char c);
int match(char left, char right);
int scanner(const char *code);

 

.cpp

#include "Stack_Pare_Match.h"


bool isLeft(char c)
{
	switch (c)
	{
	case '<' :
	case '(' :
	case '[' :
	case '{' :
	case '\'':
	case '\"':
		return true;
	default:
		return false;
	}
}

bool isRight(char c)
{
	switch (c)
	{
	case '>':
	case ')':
	case ']':
	case '}':
	case '\'':
	case '\"':
		return true;
	default:
		return false;
	}
}

int match(char left, char right)
{
	int ret = 0;
	switch (left)
	{
	case '<':
		ret = (right == '>');
		break;
	case '(':
		ret = (right == ')');
		break;
	case '[':
		ret = (right == ']');
		break;
	case '{':
		ret = (right == '}');
		break;
	case '\'':
		ret = (right == '\'');
		break;
	case '\"':
		ret = (right == '\"');
		break;
	default:
		ret = 0;
		break;
	}
	return ret;
}

int scanner(const char *code)
{
	assert(code != NULL);
	LinkStack *stack = LinkList_Create();
	assert(stack != NULL);
	int i = 0;
	while (code[i] != '\0')
	{
		if (isLeft(code[i]))
		{
			LinkStack_Push(stack, (void*)(code + i));
		}
		if (isRight(code[i]))
		{
			char *c = (char*)LinkStack_Top(stack);
			if ((c == NULL) || !match(*c, code[i]))
			{
				printf("%c does not match!\n", code[i]);
				return ERROR;
			}
			LinkStack_Pop(stack);
		}
		i++;
	}
	if (LinkStack_Size(stack) == 0)
	{
		printf("succed!\n");
	}
	else
	{
		while (LinkStack_Size(stack) > 0)
		{
			printf("%c   ", *(char*)LinkStack_Pop(stack));
		}
		printf("does not match!\n");
	}
	LinkStack_Destroy(stack);
	return OK;
}


int main()
{
	const char *code = "#include <stdio.h int main( { int arr[5][5];int (*p)[5];p=arr;}";
	
	scanner(code);
	_CrtDumpMemoryLeaks();
	system("pause");
	return 0;
}