Codeforces Round #633 (Div. 2) A ~~C

A

水题：找规律

cin>>n;
cout<<n<<endl;

B

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define pb push_back
#define mp make_pair
const ll maxn = 1e5 + 10;
const ll mod = 1e9+7;
const ll inf = 0x3f3f3f3f3f3f3f3f;
ll a[maxn];
int main() {
	ios::sync_with_stdio(0);
	ll t;
	cin>>t;
	while(t--){
		ll n;
		cin>>n;
		for(int i=0;i<n;i++)	cin>>a[i];
		sort(a,a+n);
		ll mid=n/2,mi=a[mid];
		cout<<mi;
		for(int i=1;;i++){
			if(mid-i>=0)	cout<<" "<<a[mid-i];
			if(mid+i<n)		cout<<" "<<a[mid+i];
			if(mid-i<=0||mid+i>=n)	 break;
		}
		cout<<endl;
	}
	return 0;
}

C

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define pb push_back
#define mp make_pair
const ll maxn = 1e5 + 10;
const ll mod = 1e9+7;
const ll inf = 0x3f3f3f3f3f3f3f3f;
ll a[maxn];
int main() {
	ios::sync_with_stdio(0);
	ll t;
	cin>>t;
	while(t--){
		ll n;
		cin>>n;
		for(int i=0;i<n;i++)	cin>>a[i];
		ll ans=-1;
		for(int i=1;i<n;i++){
			if(a[i]<a[i-1]){
				ll mid=a[i-1]-a[i];
				a[i]=a[i-1];
				ans=max(ans,mid);
			}
		}
		if(ans==-1){
			cout<<"0\n";
			continue;
		}
		ll re=0;
		while(ans){
			ans/=2;
			re++;
		}
		cout<<re<<endl;
	}
	return 0;
}