题解 | #打印极值点下标#

#include <stdio.h>

int main() {
    int n;
    while ((scanf("%d", &n)) != EOF) {
        int Arr[n];
        for (int i = 0; i < n; i++) {
            scanf("%d", &Arr[i]);
        }
        int Brr[n];
        int k = 0;
        for (int j = 0; j < n; j++) {
            if (j == 0 && (Arr[j] != Arr[j + 1])) {
                Brr[k++] = j;
            } else if (j == n - 1 && (Arr[j] != Arr[j - 1])) {
                Brr[k++] = j;
            }

            else if ((Arr[j] > Arr[j + 1] && Arr[j] > Arr[j - 1]) || (Arr[j] < Arr[j + 1] &&
                     Arr[j] < Arr[j - 1])) {
                Brr[k++] = j;
            }
        }
        for (int l = 0; l < k; l++) {
            printf("%d ", Brr[l]);
        }
        printf("\n");
    }
    return 0;
}