https://codeforces.com/contest/1301/problem/B

https://codeforces.com/contest/1301/problem/B
如果填的这个数特别大，显然不优，如果数特别小，也不优，所以它是凸函数，可以二分（整数单峰函数二分模板题

#include <iostream>
#include <cstdio>
#include <queue>
#include <algorithm>
#include <cmath>
#include <cstring>
#define inf 2147483647
#define N 1000010
#define p(a) putchar(a)
#define For(i,a,b) for(long long i=a;i<=b;++i)

using namespace std;
long long T,n,l,r,mid;
long long a[N],b[N];
void in(long long &x){
    long long y=1;char c=getchar();x=0;
    while(c<'0'||c>'9'){if(c=='-')y=-1;c=getchar();}
    while(c<='9'&&c>='0'){ x=(x<<1)+(x<<3)+c-'0';c=getchar();}
    x*=y;
}
void o(long long x){
    if(x<0){p('-');x=-x;}
    if(x>9)o(x/10);
    p(x%10+'0');
}

long long f(long long x){
    long long Max=0;
    For(i,1,n) if(a[i]!=-1) b[i]=a[i];else b[i]=x;
    For(i,1,n-1) Max=max(Max,b[i]>b[i+1]?b[i]-b[i+1]:b[i+1]-b[i]);
    return Max;
}

signed main(){
    in(T);
    while(T--){
        in(n);
        For(i,1,n) in(a[i]);
        l=1;r=1e10;
        while(l<r){
            mid=(l+r)>>1;
            if(f(mid-1)<=f(mid)) r=mid;
            else l=mid+1;
        }
        o(f(l-1));p(' ');o(l-1);p('\n');
    }
    return 0;
}