A12661 | Special Segments of Permutation
时间限制1s
内存限制256MB
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题目描述
You are given a permutation $p$ of $n$ integers $1$ , $2$ , ..., $n$ (a permutation is an array where each element from $1$ to $n$ occurs exactly once).
Let's call some subsegment $p[l, r]$ of this permutation special if $p_l + p_r = \max \limits_{i = l}^{r} p_i$ . Please calculate the number of special subsegments.
Let's call some subsegment $p[l, r]$ of this permutation special if $p_l + p_r = \max \limits_{i = l}^{r} p_i$ . Please calculate the number of special subsegments.
输入格式
The first line contains one integer $n$ ( $3 \le n \le 2 \cdot 10^5$ ).
The second line contains $n$ integers $p_1$ , $p_2$ , ..., $p_n$ ( $1 \le p_i \le n$ ). All these integers are pairwise distinct.
The second line contains $n$ integers $p_1$ , $p_2$ , ..., $p_n$ ( $1 \le p_i \le n$ ). All these integers are pairwise distinct.
输出格式
Print the number of special subsegments of the given permutation.
输入输出样例
输入 #1
5 3 4 1 5 2
输出 #1
2
输入 #2
3 1 3 2
输出 #2
1
Special subsegments in the first example are $[1, 5]$ and $[1, 3]$ .
The only special subsegment in the second example is $[1, 3]$ .
The only special subsegment in the second example is $[1, 3]$ .
C++ 编辑器
输入
输出
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评测结果：Accepted