题解 | 打印极值点下标

#include <iostream>
#include <string>
#include <algorithm>
#include <cstdio>

using namespace std;

const int N = 21;

int n;
int a[N];

void res (int n) {
    if (a[0] != a[1]) cout << 0 << " ";
    for (int i = 1; i < n - 1; i++) {
        if ((a[i] > a[i - 1] && a[i] > a[i + 1]) || (a[i] < a[i - 1] && a[i] < a[i + 1])) cout << i << " ";
    }
    if (a[n -1] != a[n - 2]) cout << n - 1 << " ";
}

int main() {
    while (cin >> n) {
        for (int i = 0; i < n; i++) cin >> a[i];
        res(n);
        cout << endl;
    }
    return 0;
}
// 64 位输出请用 printf("%lld")