Codeforces Round #313 (Div. 2) D. Equivalent Strings

D. Equivalent Strings

Time Limit: 2 Sec

Memory Limit: 256 MB

题目连接

http://codeforces.com/contest/559/problem/B

Description

Today on a lecture about strings Gerald learned a new definition of string equivalency. Two strings a and b of equal length are calledequivalent in one of the two cases:

1. They are equal.
2. If we split string a into two halves of the same size a1 and a2, and string b into two halves of the same size b1 and b2, then one of the following is correct:
   1. a1 is equivalent to b1, and a2 is equivalent to b2
   2. a1 is equivalent to b2, and a2 is equivalent to b1

As a home task, the teacher gave two strings to his students and asked to determine if they are equivalent.

Gerald has already completed this home task. Now it's your turn!

Input

The first two lines of the input contain two strings given by the teacher. Each of them has the length from 1 to 200 000 and consists of lowercase English letters. The strings have the same length.

Output

Print "YES" (without the quotes), if these two strings are equivalent, and "NO" (without the quotes) otherwise.

Sample Input

aaba
abaa

Sample Output

YES

input

aabb
abab

output

NO

HINT

题意

判断俩字符串是否类似就是说一半的一半是否相同，交换的情况下又是否相同

题解：

暴力

代码

#include <iostream>
#include <stdio.h>
#include <vector>
#include <algorithm>
#include <string>
#include <stack>
#include <math.h>
#include <vector>
#include <string.h>
using namespace std;

typedef __int64 ll;
const int INF = (int)1E9+10;
inline ll read()
{
    ll x=0,f=1;char ch=getchar();
    while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
    while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}
    return x*f;
}

//*******************************
bool isEqual(char* a,char* b,int len)
{
   bool flag=true;
    for(int i=0;i<len&&flag;i++)
    {
        if(a[i]!=b[i]) flag=false;
    }
    if(flag) return true;
    if(len&1) return false;
    return (isEqual(a,b,len/2)&&isEqual(a+len/2,b+len/2,len/2))||(isEqual(a+len/2,b,len/2)&&isEqual(a,b+len/2,len/2));
}

int main()
{
      char a[200100];
      char b[201000];
    scanf("%s%s",a,b);
    int len=strlen(a);
    if(len%2)
    {
        if(strcmp(a,b)==0)
        {
            printf("YES
");
        }
        else printf("NO
");
        return 0;
    }
    if(isEqual(a,b,len))
    {
            printf("YES
");
        }
        else printf("NO
");

    return 0;
}