Parentheses Balance——括号匹配

  Parentheses Balance 

You are given a string consisting of parentheses () and []. A string of this type is said to be correct:

(a)
if it is the empty string
(b)
if A and B are correct, AB is correct,
(c)
if A is correct,  (A  ) and  [A  ] is correct.

Write a program that takes a sequence of strings of this type and check their correctness. Your program can assume that the maximum string length is 128.

Input 

The file contains a positive integer 
n
 and a sequence of 
n
 strings of parentheses  ()
 and  []
, one string a line.

Output 

A sequence of  Yes
 or  No
 on the output file.

Sample Input 

3
([])
(([()])))
([()[]()])()

Sample Output 

Yes
No
Yes

经典的括号匹配问题,渣渣惭愧地错了两遍。。。。。。

开出一个栈,用来存放从前到后的前括号

括号不匹配,有三种情况:

(1)找到后括号,但是栈顶的前括号和改后括号不匹配。

(2)找到后括号,但是栈内已经没有括号了。

(3)字符串遍历完了,但是站内还没有空,即还有前括号没有与之对应。(丢掉的就是这种情况,开始还以为是应为字符串内有括号没有处理掉呢,后来又仔细读了读题,发现题目中只有这两种括号,没有其他字符。)

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

int main()
{
    char zhan[200],ss[200];
    int top,low,i,j,l;
    scanf("%d",&j);
    getchar();
    while(j--)
    {
        int bj = 1;
        gets(ss);
        memset(zhan,0,sizeof(zhan));
        top = low = -1;
        l = strlen(ss);
        for(i = 0; i < l; i++)
        {
            if(ss[i] == '(' || ss[i] == '[')
            {
                zhan[++top] = ss[i];
            }
            else if(ss[i] == ')')
            {
                if(zhan[top] == '(')
                    top--;
                else
                {
                    bj = 0;
                    break;
                }
            }
            else if(ss[i] == ']')
            {
                if(zhan[top] == '[')
                    top--;
                else
                {
                    bj = 0;
                    break;
                }
            }
            else
            {
                bj = 0;
                break;
            }
        }
        if(i == l && top != low)
            bj = 0;
        if(bj == 0)
        {
            printf("No\n");
        }
        else
        {
            printf("Yes\n");
        }
    }
    return 0;
}
    原文作者:括号匹配问题
    原文地址: https://blog.csdn.net/A_Happy_ACMer/article/details/43051117
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