public class stack {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
System.out.println("请输入您想输入的字符串：");
String str = scanner.next();
int i,next;
int top = 0;
int len = str.length();
int mid = len/2-1;
String a[] = new String[len/2];
String s[] = new String[len/2+1];
for(i=0;i<=mid;i++){
s[++top] = a[i];
}
if(len%2==0)
next=mid+1;
else
next=mid+2;
for(i=next;i<=len-1;i++) {
if(a[i]!=s[top])
break;
top--;
}
if(top==0)
System.out.println("YES");
else
System.out.println("NO");
}
}
判断的算法是对的，问题出在数组，该怎么改？谢谢
