【CF1029A】Many Equal Substrings（模拟）

题意：给定一个长度为n的串s，要求构造一个长度最小的使s出现了k次的串，可以重叠

n<=50,k<=50

思路：计算一下前后缀相同长度

#include<cstdio>
#include<cstring>
#include<string>
#include<cmath>
#include<iostream>
#include<algorithm>
#include<map>
#include<set>
#include<queue>
#include<vector>
using namespace std;
typedef long long ll;
typedef unsigned int uint;
typedef unsigned long long ull;
typedef pair<int,int> PII;
typedef vector<int> VI;
#define fi first
#define se second 
#define MP make_pair
#define N   5100000
#define MOD 1e9+7 
#define eps 1e-8 
#define pi acos(-1)

char ch[100];

            

int read()
{ 
   int v=0,f=1;
   char c=getchar();
   while(c<48||57<c) {if(c=='-') f=-1; c=getchar();}
   while(48<=c&&c<=57) v=(v<<3)+v+v+c-48,c=getchar();
   return v*f;
}

void swap(int &x,int &y)
{
    int t=x;x=y;y=t;
}


        
int main()
{
    //freopen("1.in","r",stdin);
    //freopen("1.out","w",stdout);
    int n,k1;
    scanf("%d%d",&n,&k1);
    scanf("%s",ch+1);
    int st=0;
    int flag;
    for(int i=n-1;i>=1;i--)
    {
         flag=1;
        int j=1;
        int k=n-i+1;
        while(k<=n&&j<=i)
        {
            if(ch[j]!=ch[k]){flag=0; break;}
            j++; k++; 
        }
        if(flag){st=j-1; break;}
    }

//    printf("%d
",st); 
    for(int i=1;i<=st;i++) printf("%c",ch[i]);
    for(int i=1;i<=k1;i++) 
     for(int j=st+1;j<=n;j++) printf("%c",ch[j]); 
    
    return 0;
}