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原题链接

题解

$a_{i-1}·2^{k_{i-1}}\le a_i·2^{k_i}$

$k_i\ge lo{g}_2(a_{i-1})-lo{g}_2(a_i)+k_{i-1}$

这里log2不能减，要在里面除，太坑了

code

#include<bits/stdc++.h>
#define ll long long
using namespace std;
ll a[100005],cnt[100006]={0};
int main()
{
    ios::sync_with_stdio(false);cout.tie(0);cin.tie(0);
    int t;
    cin>>t;

    while(t--)
    {
        int n;
        cin>>n;

        for(int i=1;i<=n;i++) cin>>a[i];
        cnt[1]=0;
        ll ans=0;
        for(int i=2;i<=n;i++)
        {
            long long m=ceil(log2(1.0*a[i-1]/a[i])+cnt[i-1]);

            cnt[i]=max(0LL,m);
            ans+=cnt[i];
        }
        cout<<ans<<'\n';
    }
    return 0;
}