Codeforces Round #787 (Div. 3)(B. Make It Increasing)

 

Bismillahir Rahmanir Rahim

///Author: Tanvir Ahmmad

///CSE,Islamic University,Bangladesh

#include<iostream>

#include<cstdio>

#include<algorithm>

#include<string>

#include<cstring>

#include<sstream>

#include<cmath>

#include<cstring>

#include<vector>

#include<queue>

#include<map>

#include<set>

#include<stack>

#include<vector>

#include<iterator>

#include <functional> ///sort(arr,arr+n,greater<int>()) for decrement of array

/*every external angle sum=360 degree

  angle find using polygon hand(n) ((n-2)*180)/n*/

///Floor[Log(b)  N] + 1 = the number of digits when any number is represented in base b

using namespace std;

typedef long long ll;

int main()

{

    ll tst,n;

    cin>>tst;

    while(tst--)

    {

        cin>>n;

        ll arr[n+5],flag=0,op=0;

        for(ll i=0;i<n;i++) cin>>arr[i];

        for(ll i=n-2;i>=0;i--)

            while(arr[i]>=arr[i+1] && arr[i]>0) arr[i]/=2,op++;

        for(ll i=0;i<n-1;i++)

            if(arr[i]>=arr[i+1]) flag=1;

        if(flag) cout<<"-1"<<endl;

        else cout<<op<<endl;

    }

    return 0;

}

///Alhamdulillah

Problem Link: https://codeforces.com/contest/1675/problem/B