CF1301B-Motarack's Birthday

对于-1而言，取相邻数最大最小中间值即可。

记得考虑非-1的数对答案也有影响。

#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
int T,minn,maxn,n,k,res,a[110000];
bool suc;
int main()
{
    for (scanf("%d",&T);T;T--)
    {
        minn = 2000000000;
        maxn = 0;
        res = 0;
        suc = false;
        scanf("%d",&n);
        for (int i = 1;i <= n;i++)
            scanf("%d",&a[i]);
        for (int i = 1;i <= n;i++)
            if (a[i] == -1)
            {
                if (i != 1 && a[i - 1] != -1) 
                {
                    maxn = max(maxn,a[i - 1]);
                    minn = min(minn,a[i - 1]);
                }
                if (i != n && a[i + 1] != -1)
                {
                    maxn = max(maxn,a[i + 1]); 
                    minn = min(minn,a[i + 1]);
                }
            }else
            {
                if (i != 1 && a[i - 1] != -1) 
                    res = max(res,abs(a[i] - a[i - 1]));
                if (i != n && a[i + 1] != -1)
                    res = max(res,abs(a[i] - a[i + 1]));
                suc = true;
            }
        k = (maxn + minn) / 2;
        if (suc) 
            printf("%d %d
",max(res,max(maxn - k,k - minn)),k);
        else
            printf("0 1
");
    }
    return 0;
}