Long Common Subsequence

AtCoder

IDagc052_a

Time2000ms

Memory256MB

Difficulty—

You are given $3$ binary strings $S_1, S_2, S_3$, each containing exactly $N$ `0`'s and $N$ `1`'s. Find a binary string of length $2N+1$, which is a subsequence of all of the strings $S_1 + S_1, S_2 + S_2, S_3 + S_3$ ($s+t$ denotes the concatenation of strings $s$ and $t$ in order). It's guaranteed that under the constraints above such a string always exists. Here a string $B$ is a subsequence of a string $A$ if $B$ can be obtained by removing zero or more characters from $A$ and concatenating the remaining characters without changing the order. You will be given $T$ test cases. Solve each of them. ## Constraints * $1 \le T \le 10^5$ * $1\le N \le 10^5$ * $S_i$ is a binary string of length $2N$ consisting of $N$ `0`'s and $N$ `1`'s. * The sum of $N$ over all test cases doesn't exceed $10^5$. ## Input Input is given from Standard Input in the following format. The first line of input is as follows: $T$ Then, $T$ test cases follow, each of which is in the following format: $N$ $S_1$ $S_2$ $S_3$ [samples]

Samples

Input #1

Output #1

010
11011

In the first case, `010` is a subsequence of `0101`, `0101`, and `1010`.
In the second case, `11011` is a subsequence of `01010101`, `00110011`, and `11001100`.

API Response (JSON)

{
  "problem": {
    "name": "Long Common Subsequence",
    "description": {
      "content": "You are given $3$ binary strings $S_1, S_2, S_3$, each containing exactly $N$ `0`'s and $N$ `1`'s. Find a binary string of length $2N+1$, which is a subsequence of all of the strings $S_1 + S_1, S_2 +",
      "description_type": "Markdown"
    },
    "platform": "AtCoder",
    "limit": {
      "time_limit": 2000,
      "memory_limit": 262144
    },
    "difficulty": "None",
    "is_remote": true,
    "is_sync": true,
    "sync_url": null,
    "sign": "agc052_a"
  },
  "statements": [
    {
      "statement_type": "Markdown",
      "content": "You are given $3$ binary strings $S_1, S_2, S_3$, each containing exactly $N$ `0`'s and $N$ `1`'s.\nFind a binary string of length $2N+1$, which is a subsequence of all of the strings $S_1 + S_1, S_2 +...",
      "is_translate": false,
      "language": "English"
    }
  ]
}

Full JSON Raw Segments