题目大意
给三个长度为n(1<=n<=100 000)的数组A,B,C。可以将A数组或者B数组左移,每次移动记一次操作,问最少多少次操作可以使得Ai+Bi=Ci,否则扣-1。
题解
比赛的时候脑子抽了...推了一个非充要条件,然后看有点假,想想会不会是字符串相关的题,然后去做核酸了。
后来发现很假,直接环形哈希就完事儿了。带上map复杂度是1
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115//This amazing code is written by Primo.Jay.Pan From CUC
//Any questions please contact me
//QQ:898021802
//Mail: primojpan@gmail.com
//. primojaypan@cuc.edu.cn
// Untitled 3.txt
// Created by Primo Jay Pan on 2022/3/22.
//While (true) RP++;
//head
//clear the array
using namespace std;
const ull mod=998244353;
const int maxn =100010;
ull A[maxn],B[maxn],C[maxn],base[maxn];
map<ull , int > MP;
int n;
inline void init()
{
base[0]=1;
for (int i=1;i<=n;i++)
base[i]=base[i-1]*mod;
}
int ans=mod;
//main
int main()
{
//freopen("Untitled 3.txt.in","r",stdin);
//freopen("Untitled 3.txt.out","w",stdout);
cin>>n;
init();
for (int i=1;i<=n;i++)
{
cin>>A[i];
A[i]=A[i-1]*mod+A[i];
}
for (int i=1;i<=n;i++)
{
cin>>B[i];
B[i]=B[i-1]*mod+B[i];
}
for (int i=1;i<=n;i++)
{
cin>>C[i];
C[i]=C[i-1]*mod+C[i];
}
for (int i=0;i<n;i++)
{
ull cur=(A[n]-A[i]*base[n-i])*base[i]+A[i];
MP[cur]=i;//A左移动i位
}
for (int i=0;i<n;i++)
{
ull cur=(B[n]-B[i]*base[n-i])*base[i]+B[i];//B左移动n位
if (MP.count(C[n]-cur))
ans=min(ans,MP[C[n]-cur]+i);
}
cout<<((ans==mod)?-1:ans)<<endl;
return 0;
}
/*
Test Data1:
Test Data2:
*/