CodeForces A. Many Equal Substrings

Posted 2021-01-14 zlrrrr

http://codeforces.com/contest/1029/problem/A

 

You are given a string $\mathrm{tt consisting\; of nn lowercase\; Latin\; letters\; and\; an\; integer\; number kk.}$

Let‘s define a substring of some string $\mathrm{ss with\; indices\; from ll to rr as s[l\dots r]s[l\dots r].}$

Your task is to construct such string $\mathrm{ss of\; minimum\; possible\; length\; that\; there\; are\; exactly kk positions ii such\; that s[i\dots i+n?1]=ts[i\dots i+n?1]=t.\; In\; other\; words,\; your\; task\; is\; to\; construct\; such\; string ss of\; minimum\; possible\; length\; that\; there\; are\; exactly kk substrings\; of ss equal\; to tt.}$

It is guaranteed that the answer is always unique.

Input

The first line of the input contains two integers $\mathrm{nn and kk (1\le n,k\le 501\le n,k\le 50)\; —\; the\; length\; of\; the\; string tt and\; the\; number\; of\; substrings.}$

The second line of the input contains the string $\mathrm{tt consisting\; of\; exactly nn lowercase\; Latin\; letters.}$

Output

Print such string $\mathrm{ss of\; minimum\; possible\; length\; that\; there\; are\; exactly kk substrings\; of ss equal\; to tt.}$

It is guaranteed that the answer is always unique.

Examples

input

Copy

3 4
aba

output

Copy

ababababa

input

Copy

3 2
cat

output

Copy

catcat

代码：

#include <bits/stdc++.h>
using namespace std;

int N, M;
string s;

int main() {
    scanf("%d%d", &N, &M);
    cin >> s;
    int temp;
    for(int i = 0; i < N; i ++) {
        if(s.substr(0, i) == s.substr(N - i, i))
            temp = i;
    }
    for(int i = 1; i < M; i ++)
        cout << s.substr(0, N - temp);
    cout << s <<endl;
    return 0;
}