Submission #479151

#	Time	Username	Problem	Language	Result	Execution time	Memory
479151		errorgorn	Diversity (CEOI21_diversity)	C++17	64 / 100	111 ms	21412 KiB

diversity

//雪花飄飄北風嘯嘯
//天地一片蒼茫

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/rope>
using namespace std;
using namespace __gnu_pbds;
using namespace __gnu_cxx;
#define ll long long
#define ii pair<ll,ll>
#define iii pair<ii,ll>
#define fi first
#define se second
#define endl '\n'
#define debug(x) cout << #x << ": " << x << endl

#define pub push_back
#define pob pop_back
#define puf push_front
#define pof pop_front
#define lb lower_bound
#define ub upper_bound

#define rep(x,start,end) for(auto x=(start)-((start)>(end));x!=(end)-((start)>(end));((start)<(end)?x++:x--))
#define all(x) (x).begin(),(x).end()
#define sz(x) (int)(x).size()

#define indexed_set tree<ll,null_type,less<ll>,rb_tree_tag,tree_order_statistics_node_update>
//change less to less_equal for non distinct pbds, but erase will bug

mt19937 rng(chrono::system_clock::now().time_since_epoch().count());

const int MOD=998244353;

ll qexp(ll b,ll p,int m){
    ll res=1;
    while (p){
        if (p&1) res=(res*b)%m;
        b=(b*b)%m;
        p>>=1;
    }
    return res;
}

ll inv(ll i){
	return qexp(i,MOD-2,MOD);
}

ll fix(ll i){
	i%=MOD;
	if (i<0) i+=MOD;
	return i;
}

ll fac[1000005];
ll ifac[1000005];

ll nCk(int i,int j){
	if (i<j) return 0;
	return fac[i]*ifac[j]%MOD*ifac[i-j]%MOD;
}

int n,q;
int arr[300005];
int cnt[300005];

int main(){
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	cin.exceptions(ios::badbit | ios::failbit);
	
	fac[0]=1;
	rep(x,1,1000005) fac[x]=fac[x-1]*x%MOD;
	ifac[1000004]=inv(fac[1000004]);
	rep(x,1000005,1) ifac[x-1]=ifac[x]*x%MOD;
	
	cin>>n>>q;
	rep(x,1,n+1) cin>>arr[x];
	rep(x,1,n+1) cnt[arr[x]]++;
	
	vector<int> v;
	rep(x,1,300005) v.pub(x);
	sort(all(v),[](int i,int j){
		if (cnt[i]!=cnt[j]) return cnt[i]>cnt[j];
		else return i<j;
	});
	
	rep(x,0,sz(v)){
		if (x%2==0) cnt[v[x]]=x/2;
		else cnt[v[x]]=-(x+1)/2;
	}
	//rep(x,1,10) cout<<cnt[x]<<" "; cout<<endl;
	
	sort(arr+1,arr+n+1,[](int i,int j){
		if (cnt[i]!=cnt[j]) return cnt[i]<cnt[j];
		else return i<j;
	});
	
	//rep(x,1,n+1) cout<<arr[x]<<" "; cout<<endl;
	
	ll ans=0;
	ll cnt=0;
	rep(x,1,n+1){
		if (arr[x-1]!=arr[x]) cnt+=x;
		else cnt++;
		ans+=cnt;
	}
	
	cout<<ans<<endl;
}

• Subtask 1: 4 / 4
• Subtask 2: 10 / 10
• Subtask 3: 8 / 8
• Subtask 4: 16 / 16
• Subtask 5: 26 / 26
• Subtask 6: 0 / 36