[解题报告]673 Parentheses Balance

  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

---

Miguel Revilla 
2000-08-14

 

 

 

 

 

 

 

 

括弧匹配，用开关做很方便

 

 

#include<stdio.h>
int Check(char *s) 
{
    int i,stack[200],idx=-1;
    for(i=0;s[i];i++) 
    {
        switch(s[i]) 
        {
            case '(':
                stack[++idx]='(';
                break;
            case '[':
                stack[++idx]='[';
                break;
            case ')':
                if(idx<0) return 0;
                if(stack[idx]=='(') idx--;
                else return 0;
                break;
            case ']':
                if(idx<0) return 0;
                if(stack[idx]=='[') idx--;
                else return 0;
                break;
        }
    }
    if(idx == -1) return 1;
    return 0;
}
int main() 
{
    int T;
    char s[200];
    scanf("%d",&T);
    getchar();
    while(T--) 
    {
        gets(s);
        if(Check(s)==0)
            puts("No");
        else
            puts("Yes");
    }
    return 0;
}