Sorted Arrays

AtCoder

IDagc013_a

Time2000ms

Memory256MB

Difficulty—

You are given an array $A$ of length $N$. Your task is to divide it into several contiguous subarrays. Here, all subarrays obtained must be sorted in either non-decreasing or non-increasing order. At least how many subarrays do you need to divide $A$ into? ## Constraints * $1 \leq N \leq 10^5$ * $1 \leq A_i \leq 10^9$ * Each $A_i$ is an integer. ## Input Input is given from Standard Input in the following format: $N$ $A_1$ $A_2$ $...$ $A_N$ [samples]

Samples

Input #1

6
1 2 3 2 2 1

Output #1

2

One optimal solution is to divide the array into $[1,2,3]$ and $[2,2,1]$.

Input #2

9
1 2 1 2 1 2 1 2 1

Output #2

Input #3

7
1 2 3 2 1 999999999 1000000000

Output #3

API Response (JSON)

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  "problem": {
    "name": "Sorted Arrays",
    "description": {
      "content": "You are given an array $A$ of length $N$. Your task is to divide it into several contiguous subarrays. Here, all subarrays obtained must be sorted in either non-decreasing or non-increasing order. At ",
      "description_type": "Markdown"
    },
    "platform": "AtCoder",
    "limit": {
      "time_limit": 2000,
      "memory_limit": 262144
    },
    "difficulty": "None",
    "is_remote": true,
    "is_sync": true,
    "sync_url": null,
    "sign": "agc013_a"
  },
  "statements": [
    {
      "statement_type": "Markdown",
      "content": "You are given an array $A$ of length $N$. Your task is to divide it into several contiguous subarrays. Here, all subarrays obtained must be sorted in either non-decreasing or non-increasing order. At ...",
      "is_translate": false,
      "language": "English"
    }
  ]
}

Full JSON Raw Segments