Codeforces Round 701 (Div. 2)
B
Replace and Keep Sorted
Codeforces
1200
原题
← AC →
翻译中…

Given a positive integer $k$, two arrays are called $k$-similar if:

翻译中…
  • they are strictly increasing;
  • they have the same length;
  • all their elements are positive integers between $1$ and $k$ (inclusive);
  • they differ in exactly one position.
翻译中…

You are given an integer $k$, a strictly increasing array $a$ and $q$ queries. For each query, you are given two integers $l_i \leq r_i$. Your task is to find how many arrays $b$ exist, such that $b$ is $k$-similar to array $[a_{l_i},a_{l_i+1}\ldots,a_{r_i}]$.

翻译中…

Input

翻译中…

The first line contains three integers $n$, $q$ and $k$ ($1\leq n, q \leq 10^5$, $n\leq k \leq 10^9$) — the length of array $a$, the number of queries and number $k$.

翻译中…

The second line contains $n$ integers $a_1, a_2, \ldots,a_n$ ($1 \leq a_i \leq k$). This array is strictly increasing  — $a_1 \lt a_2 \lt \ldots \lt a_n$.

翻译中…

Each of the following $q$ lines contains two integers $l_i$, $r_i$ ($1 \leq l_i \leq r_i \leq n$).

翻译中…

Output

翻译中…

Print $q$ lines. The $i$-th of them should contain the answer to the $i$-th query.

翻译中…

Note

翻译中…

In the first example:

翻译中…

In the first query there are $4$ arrays that are $5$-similar to $[2,4]$: $[1,4],[3,4],[2,3],[2,5]$.

翻译中…

In the second query there are $3$ arrays that are $5$-similar to $[4,5]$: $[1,5],[2,5],[3,5]$.

翻译中…

样例

Input #1
4 2 5
1 2 4 5
2 3
3 4
Output #1
4
3
InputCopy OutputCopy
Input #2
6 5 10
2 4 6 7 8 9
1 4
1 2
3 5
1 6
5 5
Output #2
8
9
7
6
9
InputCopy OutputCopy
题目信息
题号
1485B
时间限制
2 s
内存限制
256 MB
标签
动态规划
模拟
数学

题面与样例版权归 Codeforces 及出题人所有;中文翻译由 AI 生成(CI 管线),如有出入请以原文为准。