Rt，我本来 mina 和 maxa 的初值都赋的 -1，然后第 1 个点 WA 了，我看了半天题解，发现人家初值赋的是 0，我改成 0 就对了，我觉得他一定大于 0，初值 -1 和 0 有什么区别吗，求大佬指教

代码，WA 90pts:

using namespace std;
const int S = 5005;
int l, n, a[S];
int mina = -1, maxa = -1;
int main() {
	cin >> l >> n;
	for (int i = 1; i <= n; i++) {
		cin >> a[i];
		mina = max(mina, min(a[i], l + 1 - a[i]));
		maxa = max(maxa, max(a[i], l + 1 - a[i]));
	}
	cout << mina << ' ' << maxa;
	return 0;
}

AC（只改了个 0）：

#include <iostream>
using namespace std;
const int S = 5005;
int l, n, a[S];
int mina = 0, maxa = 0;
int main() {
	cin >> l >> n;
	for (int i = 1; i <= n; i++) {
		cin >> a[i];
		mina = max(mina, min(a[i], l + 1 - a[i]));
		maxa = max(maxa, max(a[i], l + 1 - a[i]));
	}
	cout << mina << ' ' << maxa;
	return 0;
}