直接模拟，能否在输入的时候就做好判断直接输出答案，评论区求

#include <iostream>
using namespace std;

int main() {
    int k;
    int arr[80];
    cin>>k;
    for (int i = 0; i < k; ++i) {
        cin >> arr[i];
    }
    for (int i = 0; i < k; ++i) {
        if (i == 0) {
            if (arr[i] != arr[i + 1]) {
                std::cout << i << " ";
            }
        } else if (i == k - 1) {
            if (arr[i] != arr[i - 1]) {
                std::cout << i << " ";
            }
        }else{
            if(arr[i]>arr[i-1]&&arr[i]>arr[i+1]||arr[i]<arr[i-1]&&arr[i]<arr[i+1]){
                std::cout << i << " ";
            }
        }
    }
}