a[n + 1] = n + 1;

int h() {
    int cnt = 0;
    for (int i = 1; i <= n; ++i)
        cnt += abs(a[i] - a[i + 1]) != 1;
    return cnt;
}

为何如此估值就没有问题，

a[0] = 0;

int h() {
    int cnt = 0;
    for (int i = 1; i <= n; ++i)
        cnt += abs(a[i] - a[i - 1]) != 1;
    return cnt;
}

而如此估值就出现问题了呢