Light OJ 1425

#include<bits/stdc++.h>
using namespace std;

typedef long long int       ll;
typedef unsigned long long int  ull;
typedef vector<int>         vi;
typedef vector<ll>          vll;
typedef vector<vi>          vvi;
typedef pair<int,int >      pii;
typedef vector< pii >       vpii;
typedef set<int>            sti;

#define sc                  scanf
#define pf                  printf
#define sci(n)              scanf("%d",&n)
#define scl(n)              scanf("%lld",&n)
#define scf(n)              scanf("%lf",&n)
#define scs(s)              scanf("%s",s)
#define pfi(n)              printf("%d",n)
#define pfl(n)              printf("%lld",n)
#define pff(n)              cout<<n
#define line                printf("\n")
#define spc                 printf(" ")
#define loop(i,x,y)         for(int i=int(x); i<=int(y); i++)
#define rloop(i,y,x)        for(int i=int(y); i>=int(x); i--)
#define cspf(i)             printf("Case %d: ", i)
#define pb                  push_back
#define mp                  make_pair
#define ff                  first
#define ss                  second
#define all(v)              v.begin(),v.end()
#define rall(v)             v.rbegin(),v.rend()
#define read()              freopen("input.txt", "r", stdin)
#define write()             freopen("output.txt", "w", stdout)
/// Constants
#define eps                 1e-9
#define PI                  acos(-1.0)  // 3.1415926535897932


int main()
{
    int t;sci(t);
    loop(j,1,t){
        int last=0,x,n,mx=0,dis,k;
        sci(n);
        vi ds(n);
        loop(i,0,n-1){
            sci(x);
            dis=x-last;
            ds[i]=dis;
            if(mx<dis){
                mx=dis;
                k=i;
               }
            last=x;
        }
        x=mx;
        loop(i,k,n-1){
            if(ds[i]>x){
                x=-1;
                break;
            }
            else if(ds[i]==x){
                x--;
            }
        }
        if(x==-1)
            mx++;
        cspf(j);
        pfi(mx);line;
    }
    return 0;
}