Submission #1005966

#	Time	Username	Problem	Language	Result	Execution time	Memory
1005966		PoPularPlusPlus	Cake 3 (JOI19_cake3)	C++17	0 / 100	1 ms	348 KiB

cake3

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pb(x) push_back(x)
#define mp(x,y) make_pair(x,y)
#define all(x) x.begin(),x.end()
#define vf first 
#define vs second
const int mod = 1000000007;
 
mt19937_64 RNG(chrono::steady_clock::now().time_since_epoch().count());

const int N = 200004;
int n , m;
vector<pair<ll,ll>> arr;
ll ans;

bool cmp(pair<int,int> a , pair<int,int> b){
	if(a.vs == b.vs)return a.vf > b.vf;
	return a.vs < b.vs;
}

struct item {
	vector<int> left , right;
};

void unite(vector<int>& a , vector<int>& b){
	vector<int> v;
	for(int i : a)v.pb(i);
	for(int i : b)v.pb(i);

	if(v.size() < m){
		return;
	}

	bool vis[v.size()];
	memset(vis,0,sizeof vis);
	int j = 0;
	int last = 1;
	set<pair<ll,int>> s;
	ll res = 0;
	ll tp[v.size()];
	for(int i = 1; i < m; i++){
		res += arr[v[i]].vf;
		s.insert(mp(arr[v[i]].vf , i));
		tp[i] = arr[v[i]].vf;
	}
	res -= 2*(arr[v[m-1]].vs - arr[v[0]].vs);
	res += arr[v[0]].vf;
	ans = max(ans , res);
	//cout << res << '\n';
	s.insert(mp(arr[v[0]].vf - 2*(arr[v[last]].vs - arr[v[j]].vs) , 0));
	tp[0] = arr[v[0]].vf - 2*(arr[v[last]].vs - arr[v[j]].vs);
	for(int i = m; i < v.size(); i++){
		res -= 2*(arr[v[i]].vs - arr[v[i-1]].vs);
		ll val = arr[v[i]].vf;
		if(val >= ((*s.begin()).vf)){
			pair<ll,int> p = *s.begin();
			s.erase(s.begin());
			//cout << p.vf << ' ';
			res -= p.vf;
			res += val;
			vis[p.vs] = 1;
			s.insert(mp(arr[v[i]].vf, i));
			tp[i] = arr[v[i]].vf;
		}
		else vis[i] = 1;
		while(j < v.size() && vis[j]){
			j++;
		}
		last = max(last , j + 1);
		while(last < v.size() && vis[last]){
			last++;
		}
		if(s.count(mp(tp[j] , j))){
			s.erase(mp(tp[j] , j));
			tp[j] = arr[v[j]].vf - 2*(arr[v[last]].vs - arr[v[j]].vs);
			s.insert(mp(tp[j] , j));
		}

		ans = max(ans , res);
		//cout << res << '\n';
	}
}

vector<int> left_merge(vector<int>& a , vector<int>& b , bool rev){
	vector<int> v;
	for(int i : a)v.pb(i);
	for(int i : b)v.pb(i);

	if(v.size() <= m){
		return v;
	}

	if(rev)reverse(all(v));

	priority_queue<pair<int,int>,vector<pair<int,int>> , greater<pair<int,int>> > pq;

	ll res = 0;
	for(int i = 0; i < m; i++){
		res += arr[v[i]].vf;
		pq.push(mp(arr[v[i]].vf , i));
		if(i){
			res -= 2*abs(arr[v[i]].vs - arr[v[i-1]].vs);
		}
	}

	ll best[v.size()];
	best[m-1] = res;

	for(int i = m; i < v.size(); i++){
		res -= 2*abs(arr[v[i]].vs - arr[v[i-1]].vs);
		if(pq.top().vf < arr[v[i]].vf){
			res -= pq.top().vf;
			pq.pop();
			pq.push(mp(arr[v[i]].vf , i));
			res += arr[v[i]].vf;
		}

		best[i] = res;
	}

	int pos = m-1;
	res = best[m-1];
	for(int i = m; i < v.size(); i++){
		if(best[i] > res){
			pos = i;
			res = best[i];
		}
	}

	while(pq.size())pq.pop();

	for(int i = 0; i < m; i++){
		pq.push(mp(arr[v[i]].vf , v[i]));
	}
	for(int i = m; i < v.size(); i++){
		if(pq.top().vf < arr[v[i]].vf){
			pq.pop();
			pq.push(mp(arr[v[i]].vf , v[i]));
		}
	}

	vector<int> toreturn;
	while(pq.size()){
		toreturn.pb(pq.top().vs);
		pq.pop();
	}

	sort(all(toreturn));

	return toreturn;
}

item merge(item a , item b){
	unite(a.right , b.left);

	vector<int> left = left_merge(a.left , b.left , 0);
	vector<int> right = left_merge(a.right , b.right , 1);


	/*for(int i : left){
		cout << i << ' ';
	}
	cout << '\n';
	for(int i : right){
		cout << i << ' ';
	}
	cout << '\n';*/

	return {left , right};
}

item dnc(int l , int r){
	//cout << "came" << endl; 

	if(l == r){
		return {{l} , {l}};
	}

	int m = (l + r)/2;

	item a = dnc(l , m);
	item b = dnc(m + 1 , r);

	//cout << l << ' ' << r << '\n';

	return merge(a , b);
}	

void solve(){
	cin >> n >> m;
	for(int i = 0; i < n; i++){
		int x , y;
		cin >> x >> y;
		arr.pb(mp(x,y));
	}

	sort(all(arr),cmp);
	ans = -1e9;
	dnc(0,n-1);
	cout << ans << '\n';
}

int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	
	//int t;
	//cin >> t;
	//while(t--)
		solve();
}

Compilation message (stderr)

cake3.cpp: In function 'void unite(std::vector<int>&, std::vector<int>&)':
cake3.cpp:32:14: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   32 |  if(v.size() < m){
      |     ~~~~~~~~~^~~
cake3.cpp:54:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   54 |  for(int i = m; i < v.size(); i++){
      |                 ~~^~~~~~~~~~
cake3.cpp:68:11: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   68 |   while(j < v.size() && vis[j]){
      |         ~~^~~~~~~~~~
cake3.cpp:72:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   72 |   while(last < v.size() && vis[last]){
      |         ~~~~~^~~~~~~~~~
cake3.cpp: In function 'std::vector<int> left_merge(std::vector<int>&, std::vector<int>&, bool)':
cake3.cpp:91:14: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   91 |  if(v.size() <= m){
      |     ~~~~~~~~~^~~~
cake3.cpp:111:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  111 |  for(int i = m; i < v.size(); i++){
      |                 ~~^~~~~~~~~~
cake3.cpp:125:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  125 |  for(int i = m; i < v.size(); i++){
      |                 ~~^~~~~~~~~~
cake3.cpp:137:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  137 |  for(int i = m; i < v.size(); i++){
      |                 ~~^~~~~~~~~~
cake3.cpp:123:6: warning: variable 'pos' set but not used [-Wunused-but-set-variable]
  123 |  int pos = m-1;
      |      ^~~

• Subtask 1: 0 / 5
• Subtask 2: 0 / 19
• Subtask 3: 0 / 76