51Nod 1347 旋转字符串 |　规律

aa
ab

YES
NO

 规律：abcabc

只需判断原始字符串

#include <bits/stdc++.h>
using namespace std;
typedef long long LL;
#define rep(i,a,n) for(int i = a; i < n; i++)
#define repe(i,a,n) for(int i = a; i <= n; i++)
#define per(i,n,a) for(int i = n; i >= a; i--)
#define clc(a,b) memset(a,b,sizeof(a))
#define INF 0x3f3f3f3f3f
#define N 1000010
char str
;
map<char,int> mm;
int main()
{
//freopen("in.txt","r",stdin);

LL n;
while(~scanf("%s",str)){
int len=strlen(str);
if(len%2!=0){
puts("NO");
continue;
}
int mid=len/2;
bool f=0;
for(int i=0;i<mid;i++){
if(str[i]!=str[mid+i]){
f=1;
break;
}
}
if(f)
{
puts("NO");
continue;
}else
{
puts("YES");
}
}
return 0;
}