题解 | 打印极值点下标

#include <iostream>
#include <vector>
using namespace std;

void isPeak(vector<int> a, int index) {

    if (index != 0 && index != a.size() - 1) {
        if (a[index] > a[index + 1] && a[index] > a[index - 1])    cout << index << " ";
        if (a[index] < a[index + 1] && a[index] < a[index - 1])    cout << index << " ";
    } else {
        if (index == 0 && a[0] != a[1])  cout << "0 ";
        if (index == a.size() - 1 &&
                a[a.size() - 1] != a[a.size() - 2])    cout << a.size() - 1;
    }
}

int main() {
    int k;
    while (cin >> k) {
        vector<int> arr(k);
        for (int i = 0; i < arr.size(); i++)   cin >> arr[i];
        for (int i = 0; i < arr.size(); i++) {
            isPeak(arr, i);
        }
        cout << endl;
    }
}