LEQ and NEQ

AtCoder

IDarc115_e

Time2000ms

Memory256MB

Difficulty—

Given is a sequence of $N$ integers $A_1,A_2,\ldots,A_N$. Print the number, modulo $998244353$, of sequences of $N$ integers $X_1,X_2,\ldots,X_N$ satisfying all of the following conditions: * $1 \leq X_i \leq A_i$ * $X_i \neq X_{i+1} (1 \leq i \leq N-1)$ ## Constraints * $2 \leq N \leq 5 \times 10^5$ * $1 \leq A_i \leq 10^9$ ## Input Input is given from Standard Input in the following format: $N$ $A_1$ $A_2$ $\ldots$ $A_N$ [samples]

Samples

Input #1

3
2 3 2

Output #1

6

The following six sequences satisfy all of the conditions.

*   $1,2,1$
*   $1,3,1$
*   $1,3,2$
*   $2,1,2$
*   $2,3,1$
*   $2,3,2$

Input #2

10
158260522 877914575 602436426 24979445 861648772 623690081 433933447 476190629 262703497 211047202

Output #2

524691026

API Response (JSON)

{
  "problem": {
    "name": "LEQ and NEQ",
    "description": {
      "content": "Given is a sequence of $N$ integers $A_1,A_2,\\ldots,A_N$. Print the number, modulo $998244353$, of sequences of $N$ integers $X_1,X_2,\\ldots,X_N$ satisfying all of the following conditions: *   $1 \\l",
      "description_type": "Markdown"
    },
    "platform": "AtCoder",
    "limit": {
      "time_limit": 2000,
      "memory_limit": 262144
    },
    "difficulty": "None",
    "is_remote": true,
    "is_sync": true,
    "sync_url": null,
    "sign": "arc115_e"
  },
  "statements": [
    {
      "statement_type": "Markdown",
      "content": "Given is a sequence of $N$ integers $A_1,A_2,\\ldots,A_N$. Print the number, modulo $998244353$, of sequences of $N$ integers $X_1,X_2,\\ldots,X_N$ satisfying all of the following conditions:\n\n*   $1 \\l...",
      "is_translate": false,
      "language": "English"
    }
  ]
}

Full JSON Raw Segments