CCF_201604-1_水题

#include<cstdio>
#include<iostream>
using namespace std;
int main()
{
    int a[1005];
    int n;
    cin >> n;
    for(int i = 1;i <= n;i++)
    {
        cin >> a[i];
    }
    int num = 0;
    for(int i = 2;i < n;i++)
    {
        if((a[i]-a[i-1])*(a[i]-a[i+1]) > 0)
        {
            num ++;
        }
    }
    cout << num << endl;
    return 0;
}