START195B——Game (Hard)（分治搜索） · znzryb

## 思路讲解

```cpp
	// 随着钱数的增加，进行的二操作总是在增加的
	function<void(ll,ll,ll,ll)> div=[&](ll k,ll kk,ll p,ll pp)->void{
		if(k>kk){
			return;
		}
		ll mid=k+kk>>1;
		ll ans=Sum[min(N,mid)];ll mp=0;
		FOR(i,p,min(mid/2,pp)){
			ll kejia=mid-i*2;
			kejia+=i;
			kejia=min(kejia,N);
			ll lans=(kejia-1+kejia-i)*i/2;
			lans+=Sum[kejia];
			if(lans>ans){
				ans=lans;
				mp=i;
			}
		}
		Ans[mid]=ans;
#ifdef LOCAL
    debug(mid);
    debug(ans);
    debug(pp);
#endif
		div(k,mid-1,p,mp);
		div(mid+1,kk,mp,pp);
	};
```

## AC代码

[https://www.codechef.com/viewsolution/1173480410](https://www.codechef.com/viewsolution/1173480410)



::: 源代码

```cpp
// Problem: Game (Hard)
// Contest: CodeChef - START195B
// URL: https://www.codechef.com/START195B/problems/GAMEHD
// Memory Limit: 256 MB
// Time Limit: 1000 ms
// 
// Powered by CP Editor (https://cpeditor.org)

#include <bits/stdc++.h>
#define all(vec) vec.begin(),vec.end()
#define pb push_back
#define SZ(a) ((int) a.size())
#define FOR(i, a, b) for (int i = (a); i <= (b); ++i)
#define ROF(i, a, b) for (int i = (a); i >= (b); --i)
#define debug(var) cerr << #var <<":"<<var<<"\n";
#define lson(var) (var<<1)
#define rson(var) ((var<<1)+1)
#define V vector

using namespace std;

using  ll = long long;using ull = unsigned long long;
using DB=double;using LD=long double;
// using i128 = __int128;
using pdd = pair<DB,DB>;using plb = pair<ll,bool>;
using pll = pair<ll,ll>;using vll=vector<ll>;
using arr3 = array<ll,3> ;using arr2 = array<ll,2>;
constexpr ll MAXN=static_cast<ll>(1e6)+10,INF=static_cast<ll>(1e17)+9; // 1e18+9也是素数
constexpr ll MAXM=(ll)1e6+10;constexpr ll MAXV=(ll)1e6+10;
constexpr ll mod=static_cast<ll>(1e9)+7;
constexpr double eps=1e-8;const double pi=acos(-1.0);

ll N,M,Q,X,K,T,lT,A[MAXN];
/*

*/
ll Sum[MAXN];
inline void __(){
	cin>>N;
	FOR(i,1,N){
		cin>>A[i];
	}
	vll sa(A+1,A+1+N);
	sort(all(sa),greater<>());
	FOR(i,1,N){
		Sum[i]=Sum[i-1]+sa[i-1];
	}
	vll Ans(2*N+5,0);
	// p is to get p Ai
	// 随着钱数的增加，进行的二操作总是在增加的
	function<void(ll,ll,ll,ll)> div=[&](ll k,ll kk,ll p,ll pp)->void{
		if(k>kk){
			return;
		}
		ll mid=k+kk>>1;
		ll ans=Sum[min(N,mid)];ll mp=0;
		FOR(i,p,min(mid/2,pp)){
			ll kejia=mid-i*2;
			kejia+=i;
			kejia=min(kejia,N);
			ll lans=(kejia-1+kejia-i)*i/2;
			lans+=Sum[kejia];
			if(lans>ans){
				ans=lans;
				mp=i;
			}
		}
		Ans[mid]=ans;
#ifdef LOCAL
    debug(mid);
    debug(ans);
    debug(pp);
#endif
		div(k,mid-1,p,mp);
		div(mid+1,kk,mp,pp);
	};
	div(1,2*N,1,N);
	FOR(i,1,2*N){
		cout<<Ans[i]<<" ";
	}
	cout<<"\n";
}

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);cout.tie(0);
	
	cin>>lT;
	while(lT--)
		__();
	return 0;
}
/*
AC
https://www.codechef.com/viewsolution/1173480410
*/
```


:::


## 心路历程（WA，TLE，MLE……）