ＢＺＯＪ3916: [Baltic2014]friends

题目：http://www.lydsy.com/JudgeOnline/problem.php?id=3916

题解：随便ｈａｓｈ．刚开始看错题ＷＡ了Ｎ发．（我连双ｈａｓｈ都写了！）

代码：

 #include<cstdio>
 #include<cstdlib>
 #include<cmath>
 #include<cstring>
 #include<algorithm>
 #include<iostream>
 #include<vector>
 #include<map>
 #include<set>
 #include<queue>
 #include<string>
 #define inf 1000000000
 #define maxn 2000000+5
 #define maxm 200000+5
 #define eps 1e-6
 #define ll unsigned int
 #define pa pair<int,int>
 #define for0(i,n) for(int i=0;i<=(n);i++)
 #define for1(i,n) for(int i=1;i<=(n);i++)
 #define for2(i,x,y) for(int i=(x);i<=(y);i++)
 #define for3(i,x,y) for(int i=(x);i>=(y);i--)
 #define for4(i,x) for(int i=head[x],y=e[i].go;i;i=e[i].next,y=e[i].go)
 #define for5(n,m) for(int i=1;i<=n;i++)for(int j=1;j<=m;j++)
 #define lch k<<1,l,mid
 #define rch k<<1|1,mid+1,r
 #define sqr(x) (x)*(x)
 #define db double
 using namespace std;
 inline int read()
 {
     int x=,f=;char ch=getchar();
     while(ch<''||ch>''){if(ch=='-')f=-;ch=getchar();}
     while(ch>=''&&ch<=''){x=*x+ch-'';ch=getchar();}
     return x*f;
 }
 int n,pos;
 char s[maxn];
 ll h[maxn],p[maxn];
 inline ll get(int x,int y){return x>y?:h[y]-h[x-]*p[y-x+];}
 ll ans,t1,t2;
 inline bool check(int x)
 {
    if(x>n>>)t1=get(,n>>),t2=(get((n>>)+,x-)*p[n-x]+get(x+,n));
    else t1=get(n-(n>>)+,n),t2=(get(,x-)*p[(n>>)-x+]+get(x+,(n>>)+));
    return t1==t2;
 }
 int main()
 {
    freopen("input.txt","r",stdin);
    freopen("output.txt","w",stdout);
    n=read();scanf("%s",s+);
    if(n%==){printf("NOT POSSIBLE\n");return ;}
    p[]=;
    for1(i,n)h[i]=h[i-]*+s[i]-'A',p[i]=p[i-]*;
    for1(i,n)if(check(i))
    {
      pos=i;
      if(!ans)ans=t1;
      else if(t1!=ans){printf("NOT UNIQUE\n");return ;};
    }
    if(!pos)printf("NOT POSSIBLE\n");
    else
    {
      if(pos>n>>)for1(i,n>>)printf("%c",s[i]);
      else for2(i,n-(n>>)+,n)printf("%c",s[i]);
      printf("\n");
    }
    return ;
 }

字体为什么忽然变了好鬼畜