hdu2609 最小表示法

Posted 2020-09-17 walfy

Give you n ( n < 10000) necklaces ,the length of necklace will not large than 100,tell me 
How many kinds of necklaces total have.(if two necklaces can equal by rotating ,we say the two necklaces are some). 
For example 0110 express a necklace, you can rotate it. 0110 -> 1100 -> 1001 -> 0011->0110. 

InputThe input contains multiple test cases. 
Each test case include: first one integers n. (2<=n<=10000) 
Next n lines follow. Each line has a equal length character string. (string only include ‘0‘,‘1‘). 
OutputFor each test case output a integer , how many different necklaces.Sample Input

4
0110
1100
1001
0011
4
1010
0101
1000
0001

Sample Output

1
2
题意：给一些长度相同的01数列，要求求出不相同的个数（经过循环相同的也算相同）
题解：最小表示法（为啥分类到kmp里面？）直接水过了，还以为要kmp之类的呢

#include<map>
#include<set>
#include<cmath>
#include<queue>
#include<stack>
#include<vector>
#include<cstdio>
#include<iomanip>
#include<cstdlib>
#include<cstring>
#include<iostream>
#include<algorithm>
#define pi acos(-1)
#define ll long long
#define mod 1000000007

using namespace std;

const int N=1000000+5,maxn=1000000+5,inf=1e9+5;

int Next[N],slen;
string str;

void getnext()
{
    Next[0]=-1;
    int k=-1;
    for(int i=1;i<slen;i++)
    {
        while(k>-1&&str[k+1]!=str[i])k=Next[k];
        if(str[k+1]==str[i])k++;
        Next[i]=k;
    }
}
int getmin()
{
    int i=0,j=1,k=0;
    while(i<slen&&j<slen&&k<slen){
        int t=str[(i+k)%slen]-str[(j+k)%slen];
        if(!t)k++;
        else
        {
            t>0 ? i=i+k+1 : j=j+k+1;
            if(i==j)j++;
            k=0;
        }
    }
    return min(i,j);
}
int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n;
    while(cin>>n){
        vector<string>v;
        for(int i=0;i<n;i++)
        {
            cin>>str;
            slen=str.size();
            str=str.substr(getmin(),slen)+str.substr(0,getmin());
            bool flag=1;
            for(int j=0;j<v.size();j++)
                if(v[j]==str)
                {
                    flag=0;
                    break;
                }
            if(flag)v.push_back(str);
        }
        cout<<v.size()<<endl;
    }
    return 0;
}

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