A900. Balanced Photo--Gold
编程题
普及+/提高
知识点
题目描述
Farmer John is arranging his $N$ cows in a line to take a photo ($1 \leq N
\leq 100,000$). The height of the $i$th cow in sequence is $h_i$, and the
heights of all cows are distinct.
As with all photographs of his cows, FJ wants this one to come out looking as
nice as possible. He decides that cow $i$ looks "unbalanced" if $L_i$ and
$R_i$ differ by more than factor of 2, where $L_i$ and $R_i$ are the number of
cows taller than $i$ on her left and right, respectively. That is, $i$ is
unbalanced if the larger of $L_i$ and $R_i$ is strictly more than twice the
smaller of these two numbers. FJ is hoping that not too many of his cows are
unbalanced.
Please help FJ compute the total number of unbalanced cows.
\leq 100,000$). The height of the $i$th cow in sequence is $h_i$, and the
heights of all cows are distinct.
As with all photographs of his cows, FJ wants this one to come out looking as
nice as possible. He decides that cow $i$ looks "unbalanced" if $L_i$ and
$R_i$ differ by more than factor of 2, where $L_i$ and $R_i$ are the number of
cows taller than $i$ on her left and right, respectively. That is, $i$ is
unbalanced if the larger of $L_i$ and $R_i$ is strictly more than twice the
smaller of these two numbers. FJ is hoping that not too many of his cows are
unbalanced.
Please help FJ compute the total number of unbalanced cows.
输入格式
The first line of input contains $N$. The next $N$ lines contain $h_1 \ldots
h_N$, each a nonnegative integer at most 1,000,000,000.
h_N$, each a nonnegative integer at most 1,000,000,000.
输出格式
Please output a count of the number of cows that are unbalanced.
输入输出样例
输入 #1
7 34 6 23 0 5 99 2
输出 #1
3
说明/提示
In this example, the cows of heights 34, 5, and 2 are unbalanced.