Divide the Problems

AtCoder

IDabc132_c

Time2000ms

Memory256MB

Difficulty—

Takahashi made $N$ problems for competitive programming. The problems are numbered $1$ to $N$, and the difficulty of Problem $i$ is represented as an integer $d_i$ (the higher, the harder). He is dividing the problems into two categories by choosing an integer $K$, as follows: * A problem with difficulty $K$ or higher will be _for ARCs_. * A problem with difficulty lower than $K$ will be _for ABCs_. How many choices of the integer $K$ make the number of problems for ARCs and the number of problems for ABCs the same? * $2 \leq N \leq 10^5$ * $N$ is an even number. * $1 \leq d_i \leq 10^5$ * All values in input are integers. ## Input Input is given from Standard Input in the following format: $N$ $d_1$ $d_2$ $...$ $d_N$ [samples]

Samples

Input #1

6
9 1 4 4 6 7

Output #1

2

If we choose $K=5$ or $6$, Problem $1$, $5$, and $6$ will be for ARCs, Problem $2$, $3$, and $4$ will be for ABCs, and the objective is achieved. Thus, the answer is $2$.

Input #2

8
9 1 14 5 5 4 4 14

Output #2

0

There may be no choice of the integer $K$ that make the number of problems for ARCs and the number of problems for ABCs the same.

Input #3

14
99592 10342 29105 78532 83018 11639 92015 77204 30914 21912 34519 80835 100000 1

Output #3

API Response (JSON)

{
  "problem": {
    "name": "Divide the Problems",
    "description": {
      "content": "Takahashi made $N$ problems for competitive programming. The problems are numbered $1$ to $N$, and the difficulty of Problem $i$ is represented as an integer $d_i$ (the higher, the harder). He is divi",
      "description_type": "Markdown"
    },
    "platform": "AtCoder",
    "limit": {
      "time_limit": 2000,
      "memory_limit": 262144
    },
    "difficulty": "None",
    "is_remote": true,
    "is_sync": true,
    "sync_url": null,
    "sign": "abc132_c"
  },
  "statements": [
    {
      "statement_type": "Markdown",
      "content": "Takahashi made $N$ problems for competitive programming. The problems are numbered $1$ to $N$, and the difficulty of Problem $i$ is represented as an integer $d_i$ (the higher, the harder).\nHe is divi...",
      "is_translate": false,
      "language": "English"
    }
  ]
}

Full JSON Raw Segments