Bracket balance
Given a string consisting of () and []. If we stipulate that the following strings are legal strings:
(1) If it is an empty string, then a legal string.
(2) If A and B are legal, then AB is also a legal string.
(3) If A is legal, then (A) and [A] are both legal strings.
Sample Input
3
([])
(([()])))
([()])()
Sample Output
Yes
No
Yes
#include<bits/stdc++.h>
using namespace std;
int main()
{
int n;
scanf("%d",&n);
vector<char>s;
char a[1000];
int i,m;
getchar();
while(n)
{
gets(a);
m=strlen(a);
if(m==0)//空字符串
{
printf("Yes\n");
n--;
continue;
}
for(i=0;i<m;i++)
{
s.push_back(a[i]);//存入容器
}
int t;
while(s.size())
{
t=0;
for(i=0;i<m-1;i++)
{
if((s[i]=='('&&s[i+1]==')')||(s[i]=='['&&s[i+1]==']'))
{
s.erase(s.begin()+i);//删除
s.erase(s.begin()+i);
t++;
}
}
if(t==0)
{
printf("No\n");
break;
}
}
if(s.size()==0)
{
printf("Yes\n");
}
s.clear();
n--;
}
}