Range Pairing Query

AtCoder

IDabc242_g

Time5000ms

Memory256MB

Difficulty—

$N$ people numbered $1,2,\dots,N$ are standing in a row. Person $i$ wears Color $A_i$. Answer $Q$ queries of the format below. * You are given integers $l$ and $r$. Considering only Person $l,l+1,\dots,r$, how many pairs of people wearing the same color can be formed at most? ## Constraints * All values in input are integers. * $1 \le N \le 10^5$ * $1 \le Q \le 10^6$ * $1 \le A_i \le N$ * $1 \le l \le r \le N$ in each query. ## Input Input is given from Standard Input in the following format: $N$ $A_1$ $A_2$ $\dots$ $A_N$ $Q$ $\mathrm{Query}_1$ $\mathrm{Query}_2$ $\vdots$ $\mathrm{Query}_Q$ Here, $\mathrm{Query}_i$ represents the $i$\-th query. Each query is in the following format: $l$ $r$ [samples]

Samples

Input #1

10
1 2 3 2 3 1 3 1 2 3
6
6 10
5 8
3 6
4 4
1 6
1 10

Output #1

2
2
1
0
3
4

We have $A=(1,2,3,2,3,1,3,1,2,3)$. This input contains six queries.
The first query is $(l, r) = (6, 10)$. By pairing Person $6, 8$ and paring Person $7, 10$, we can form two pairs of people wearing the same color.
The second query is $(l, r) = (5, 8)$. By pairing Person $5, 7$ and paring Person $6, 8$, we can form two pairs of people wearing the same color.
There can be a query where $l=r$.

API Response (JSON)

{
  "problem": {
    "name": "Range Pairing Query",
    "description": {
      "content": "$N$ people numbered $1,2,\\dots,N$ are standing in a row. Person $i$ wears Color $A_i$. Answer $Q$ queries of the format below. *   You are given integers $l$ and $r$. Considering only Person $l,l+1,\\",
      "description_type": "Markdown"
    },
    "platform": "AtCoder",
    "limit": {
      "time_limit": 5000,
      "memory_limit": 262144
    },
    "difficulty": "None",
    "is_remote": true,
    "is_sync": true,
    "sync_url": null,
    "sign": "abc242_g"
  },
  "statements": [
    {
      "statement_type": "Markdown",
      "content": "$N$ people numbered $1,2,\\dots,N$ are standing in a row. Person $i$ wears Color $A_i$.\nAnswer $Q$ queries of the format below.\n\n*   You are given integers $l$ and $r$. Considering only Person $l,l+1,\\...",
      "is_translate": false,
      "language": "English"
    }
  ]
}

Full JSON Raw Segments