C语言 南阳理工ACM 2 括号配对问题

 #include<stdio.h>
#include<string.h>
int main()
{
int n,btop,i,len;
char a[10010],b[10010];
scanf("%d",&n);
while(n--){
btop=1;
memset(a,0,sizeof(a));
memset(b,0,sizeof(b));
scanf("%s",a);
len=strlen(a);
b[1]=a[0];
btop=2;
for(i=1;i<len;){
b[btop++]=a[i++];
while(btop>1&&(/*b[btop-2]-b[btop-1]==1||*/b[btop-2]-b[btop-1]==-1||/*b[btop-2]-b[btop-1]==2||*/b[btop-2]-b[btop-1]==-2))
{
btop=btop-2;
}
}
if(btop==1)
printf("Yes\n");
else 
printf("No\n");
}
return 0;
}