Problem p02937 - Generation 2

Orig Description

Score : 500 points
Problem StatementGiven are two strings s and t consisting of lowercase English letters. Determine if there exists an integer i satisfying the following condition, and find the minimum such i if it exists.
Let s' be the concatenation of 10^{100} copies of s. t is a subsequence of the string {s'}_1{s'}_2\ldots{s'}_i (the first i characters in s').
Notes
A subsequence of a string a is a string obtained by deleting zero or more characters from a and concatenating the remaining characters without changing the relative order. For example, the subsequences of contest include net, c, and contest.
Constraints
1 \leq |s| \leq 10^5
1 \leq |t| \leq 10^5
s and t consists of lowercase English letters.
InputInput is given from Standard Input in the following format:
s
t
OutputIf there exists an integer i satisfying the following condition, print the minimum such i; otherwise, print -1.
Sample Input 1contest
son
Sample Output 110
t = son is a subsequence of the string contestcon (the first 10 characters in s' = contestcontestcontest...), so i = 10 satisfies the condition.
On the other hand, t is not a subsequence of the string contestco (the first 9 characters in s'), so i = 9 does not satisfy the condition.
Similarly, any integer less than 9 does not satisfy the condition, either. Thus, the minimum integer i satisfying the condition is 10.
Sample Input 2contest
programming
Sample Output 2-1
t = programming is not a substring of s' = contestcontestcontest.... Thus, there is no integer i satisfying the condition.
Sample Input 3contest
sentence
Sample Output 333
Note that the answer may not fit into a 32-bit integer type, though we cannot put such a case here.

Extracted Specification

Canonicalized Input Description:

A string \(s\) consisting of lowercase English letters (1 ≤ |s| ≤ 10^5).
A string \(t\) consisting of lowercase English letters (1 ≤ |t| ≤ 10^5).

### Example Input:

```
contest
son
```

### Function Signature:
Write a function f(s, t) that takes in the input.
```python
def f(s: str, t: str):
    '''
    s: a string
    t: a string
    '''
```

Test Case Generator

Certainly! Here is a test case generator for the given problem statement:

```python
import random
import string

def tcgen():
    # Generate a random length for string s and t within the given constraints
    len_s = random.randint(1, 10**5)
    len_t = random.randint(1, 10**5)
    
    # Generate random strings s and t of the specified lengths
    s = ''.join(random.choices(string.ascii_lowercase, k=len_s))
    t = ''.join(random.choices(string.ascii_lowercase, k=len_t))
    
    return s, t

# Generate a test case
s, t = tcgen()
print(s)
print(t)
```

This generator follows the constraints of the problem:
- Length of `s` and `t` are between 1 and 100,000.
- Both strings `s` and `t` consist of lowercase English letters.

You can run this generator multiple times to create different test cases for the problem.

Extract Arguments

def extract_arguments(fh):
    s = fh.readline().strip()
    t = fh.readline().strip()
    return s, t