7648: [CSES Problem Set] Substring Order I
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Description
You are given a string of length $n$.
If all of its distinct substrings are ordered lexicographically, what is the $k$-th smallest of them?
If all of its distinct substrings are ordered lexicographically, what is the $k$-th smallest of them?
Input
The first input line has a string of length $n$ that consists of characters a–z.
The second input line has an integer $k$.
The second input line has an integer $k$.
Output
Print the $k$-th smallest distinct substring in lexicographical order.
Constraints
$1≤n≤10^5$
$1 \le k \le \frac{n(n+1)}{2}$
It is guaranteed that $k$ does not exceed the number of distinct substrings.
$1 \le k \le \frac{n(n+1)}{2}$
It is guaranteed that $k$ does not exceed the number of distinct substrings.
Sample 1 Input
babaacbaab
10
Sample 1 Output
aba
The 10 smallest distinct substrings in order are a, aa, aab, aac, aacb, aacba, aacbaa, aacbaab, ab, and aba.