栈的应用——括号匹配

//括号匹配问题
void MatchBrackets(char *buf, int len)
{
    Stack s;
    StackInit(&s);
    int i = 0;
    assert(buf);
    for (i = 0; i < len; i++)
    {
        //如果是左括号，则将左括号入栈
        if (('(' == buf[i]) ||
            ('[' == buf[i]) ||
            ('{' == buf[i]))
        {
            StackPush(&s, buf[i]);
        }

        //如果是右括号，则与栈顶元素比较，如果匹配，则出栈进行下轮
        //若不匹配则直接退出
        if ((')' == buf[i]) ||
            (']' == buf[i]) ||
            ('}' == buf[i]))
        {
            if (0 == EmptyStack(&s))
            {
                printf("不匹配，右括号多于左括号\n");
                return;
            }
            else
            {
                switch (buf[i])
                {
                case ')':
                    if ('(' == StackTop(&s))
                    {
                        StackPop(&s);
                        break;
                    }
                    else
                    {
                        printf("不匹配,左右括号次序不匹配\n");
                        return;
                    }

                case ']':
                    if ('[' == StackTop(&s))
                    {
                        StackPop(&s);
                        break;
                    }
                    else
                    {
                        printf("不匹配,左右括号次序不匹配\n");
                        return;
                    }

                case '}':
                    if ('{' == StackTop(&s))
                    {
                        StackPop(&s);
                        break;
                    }
                    else
                    {
                        printf("不匹配,左右括号次序不匹配\n");
                        return;
                    }

                default:
                    return;
                }
            }
        }

    }

    //判断栈是否为空
    if (0 == EmptyStack(&s))
    {
        //若栈为空则匹配
        printf("括号匹配\n");
        return;

    }

    //栈不为空
    printf("不匹配，左括号多于右括号\n");
    return;
}

test.c

//测试括号匹配问题
test1()
{
    char buf1[] = "(())abc{[(])}";  //左右括号次序不匹配
    char buf2[] = "(()))abc{[]}";   //右括号多于左括号
    char buf3[] = "(()()abc{[]}";   //左括号多于右括号
    char buf4[] = "(())abc{[]()}";  //匹配正确

    MatchBrackets(buf1, strlen(buf1));
    MatchBrackets(buf2, strlen(buf2));
    MatchBrackets(buf3, strlen(buf3));
    MatchBrackets(buf4, strlen(buf4));
}

int main()
{
    test1();

    system("pause");
    return 0;
}