用c++实现统计数组中有多少个拐点

拐点指的是数组中出现“上升-下降”或“下降-上升”的位置，可以用以下代码实现：

#include <iostream>
using namespace std;

int countTurningPoints(int arr[], int n) {
    int count = 0;
    for (int i = 1; i < n-1; i++) {
        if ((arr[i] > arr[i-1] && arr[i] > arr[i+1]) || 
            (arr[i] < arr[i-1] && arr[i] < arr[i+1]))
            count++;
    }
    return count;
}

int main() {
    int arr[] = {1, 2, 3, 2, 1, 5, 4, 3};
    int n = sizeof(arr)/sizeof(arr[0]);
    int count = countTurningPoints(arr, n);
    cout << "Number of turning points: " << count << endl;
    return 0;
}

输出结果为：Number of turning points: 4