Alone

AtCoder

IDabc346_g

Time3000ms

Memory256MB

Difficulty—

You are given an integer sequence $A = (A_1, A_2, \ldots, A_N)$. Find the number of pairs of integers $(L, R)$ that satisfy the following conditions: * $1 \leq L \leq R \leq N$ * There is a number that appears exactly once among $A_L, A_{L + 1}, \ldots, A_R$. More precisely, there is an integer $x$ such that exactly one integer $i$ satisfies $A_i = x$ and $L \leq i \leq R$. ## Constraints * $2 \leq N \leq 2 \times 10^5$ * $1 \leq A_i \leq N$ * All input values are integers. ## Input The input is given from Standard Input in the following format: $N$ $A_1$ $A_2$ $\ldots$ $A_N$ [samples]

Samples

Input #1

5
2 2 1 2 1

Output #1

12

$12$ pairs of integers satisfy the conditions: $(L, R) = (1, 1), (1, 3), (1, 4), (2, 2), (2, 3), (2, 4), (3, 3), (3, 4), (3, 5), (4, 4), (4, 5), (5, 5)$.

Input #2

4
4 4 4 4

Output #2

Input #3

10
1 2 1 4 3 3 3 2 2 4

Output #3

API Response (JSON)

{
  "problem": {
    "name": "Alone",
    "description": {
      "content": "You are given an integer sequence $A = (A_1, A_2, \\ldots, A_N)$. Find the number of pairs of integers $(L, R)$ that satisfy the following conditions: *   $1 \\leq L \\leq R \\leq N$ *   There is a numbe",
      "description_type": "Markdown"
    },
    "platform": "AtCoder",
    "limit": {
      "time_limit": 3000,
      "memory_limit": 262144
    },
    "difficulty": "None",
    "is_remote": true,
    "is_sync": true,
    "sync_url": null,
    "sign": "abc346_g"
  },
  "statements": [
    {
      "statement_type": "Markdown",
      "content": "You are given an integer sequence $A = (A_1, A_2, \\ldots, A_N)$.\nFind the number of pairs of integers $(L, R)$ that satisfy the following conditions:\n\n*   $1 \\leq L \\leq R \\leq N$\n*   There is a numbe...",
      "is_translate": false,
      "language": "English"
    }
  ]
}

Full JSON Raw Segments