Submission #854326

#	Time	Username	Problem	Language	Result	Execution time	Memory
854326		Juan	Swap Swap Sort (CCO21_day1problem1)	C++17	25 / 25	3690 ms	80876 KiB

Main

#include<bits/stdc++.h>
using namespace std;
#define int long long
#define tii tuple<int,int,int>
#define pii pair<int,int>
#define ff first
#define ss second
#define all(x) x.begin(),x.end()
#define pb push_back
const int maxn = 1e5+5, INF=0x3f3f3f3f, MOD=1e9+7;

int bit[maxn];
map<pii,int> mp;
vector<int> cnt[maxn];

void upd(int x){
	for(; x<maxn; x+=x&-x) bit[x]++;
}

int query(int x){
	int rt=0;
	for(; x>0; x-=x&-x) rt+=bit[x];
	return rt;
}

int bbin(int id, int x){
	int l=0, r=cnt[id].size()-1;
	while(l<=r){
		int m = (l+r)/2;
		if(cnt[id][m]<x) l=m+1;
		else r=m-1;
	}
	return l;
}

int calc(int a, int b){
	int rt=0;

	if(cnt[a].size()<=cnt[b].size()){
		for(int x : cnt[a]){
			rt += bbin(b,x);
		}
	}
	else{
		for(int x : cnt[b]){
			rt += cnt[a].size() - bbin(a,x);
		}
	}

	return rt;
}

int32_t main(){
	int n,k,q; cin >> n >> k >> q;

	vector<int> v(n);
	for(int i=0; i<n; i++){
		cin >> v[i];
		cnt[v[i]].push_back(i);
	}

	int ans=0;
	for(int i=0; i<n; i++){
		ans += query(k)-query(v[i]);
		upd(v[i]);
	}

	vector<int> target(k+1);
	for(int i=1; i<=k; i++) target[i]=i;
	while(q--){
		int id; cin >> id;
		int a=target[id], b=target[id+1];
		swap(target[id],target[id+1]);

		pii pr = {min(a,b),max(a,b)};

		if(mp.find(pr)==mp.end()) mp[pr] = calc(a,b);
		int& inv = mp[pr];

		int aux = cnt[a].size()*cnt[b].size()-inv;
		ans += aux-inv;
		inv = aux;

		cout << ans << '\n';
	}
}

• Subtask 1: 3 / 3
• Subtask 2: 3 / 3
• Subtask 3: 5 / 5
• Subtask 4: 14 / 14