https://codeforces.com/contest/1301/problem/B
If you fill this number is particularly large, is obviously not good, especially if the number is small, not excellent, so it is a convex function, can be half (half integer unimodal function template title
#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 ( ' ' ); or (l- 1 ); p ( ' \ n ' ); } Return 0 ; }