求波峰波谷最大值

#include <iostream>
using namespace std;

void scanPeak(int arr[], int length, int* pvlst)
{
    int i = 0;
    int curr_peak = 0;
    int curr_val = 0;
    bool is_continue = true;
 
    for (i = 1; i < length-1; i++)
    {
        if ((arr[i] < arr[i-1]) && (arr[i] < arr[i+1]))
        {
            pvlst[i] = -1;
        }
        else if ((arr[i] > arr[i-1]) && (arr[i] > arr[i+1]))
        {
            pvlst[i] = 1;
        }
    }
 
    if (arr[0] < arr[1])
        pvlst[0] = -1;
    else if (arr[0] > arr[1])
        pvlst[0] = 1;
 
    if (arr[length-1] < arr[length-2])
        pvlst[length-1] = -1;
    else if (arr[length-1] > arr[length-2])
        pvlst[length-1] = 1;
}

void maxNeighboringPeak(int arr[], int length)
{
    int i = 0;
    int * pvlst = NULL;
    int peak = 0;
    int vall = 0;
    int pair = 0;
    int max = 0;
 
    pvlst = new int[length];
    memset(pvlst, 0, sizeof(int)*length);
 
    scanPeak(arr, length, pvlst);
 
    for (i = 0; i < length; i++)
    {
        cout << pvlst[i] << "  ";
    }
    cout << endl << endl;
 
    for (i = 0; i < length; i++)
    {
        if (pvlst[i] == 1)
        {
            peak = i;
            pair++;
        }
 
        if (pvlst[i] == -1)
        {
            vall = i;
            pair++;
        }
 
        if (2 == pair)
        {
            pair = 0;
            if (arr[peak]-arr[vall] > max)
                max = arr[peak]-arr[vall];
        }
    }
 
    cout << max << endl;
 
    delete[] pvlst;
    pvlst = NULL;
}
 
int main()
{
    //int arr[6] = {2, 3, 6, 5, 7, 9};
    //int arr[5] = {2, 3, 6, 5, 7};
    int arr[7] = {2, 3, 6, 5, 7, 9, 10};
 
    int length = sizeof(arr)/sizeof(arr[0]);
 
    maxNeighboringPeak(arr, length);
 
    cout<<endl;
 
    cin >> length;
    return 0;
}