Strings of Impurity

AtCoder

IDabc138_e

Time2000ms

Memory256MB

Difficulty—

Given 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 $s'$). ## Constraints * $1 \leq |s| \leq 10^5$ * $1 \leq |t| \leq 10^5$ * $s$ and $t$ consists of lowercase English letters. ## Input Input is given from Standard Input in the following format: $s$ $t$ [samples] ## 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`.

Samples

Input #1

contest
son

Output #1

10

$t =$ `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 $10$.

Input #2

contest
programming

Output #2

\-1

$t =$ `programming` is not a substring of $s' =$ `contestcontestcontest...`. Thus, there is no integer $i$ satisfying the condition.

Input #3

contest
sentence

Output #3

33

Note that the answer may not fit into a $32$\-bit integer type, though we cannot put such a case here.

API Response (JSON)

{
  "problem": {
    "name": "Strings of Impurity",
    "description": {
      "content": "Given 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. *  ",
      "description_type": "Markdown"
    },
    "platform": "AtCoder",
    "limit": {
      "time_limit": 2000,
      "memory_limit": 262144
    },
    "difficulty": "None",
    "is_remote": true,
    "is_sync": true,
    "sync_url": null,
    "sign": "abc138_e"
  },
  "statements": [
    {
      "statement_type": "Markdown",
      "content": "Given 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.\n\n*  ...",
      "is_translate": false,
      "language": "English"
    }
  ]
}

Full JSON Raw Segments