Submission #983971

#	Time	Username	Problem	Language	Result	Execution time	Memory
983971		phoenix0423	Carnival Tickets (IOI20_tickets)	C++17	100 / 100	1062 ms	76432 KiB

tickets

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pll;
#define pb push_back
#define eb emplace_back
#include "tickets.h"
const int maxn = 1505;
const ll INF = 1e18;
// ll dp[maxn][maxn];

long long find_maximum(int k, std::vector<std::vector<int>> x) {
	int n = x.size();
	int m = x[0].size();
	vector<vector<int>> ans(n, vector<int>(m, -1));
	ll cost = 0;
	multiset<pll> stl, str; // l : l -> r, r : r -> l
	vector<int> l(n), r(n);
	auto rid = [&](int i) -> void {
		if(l[i]) stl.erase({x[i][r[i]] + x[i][l[i] - 1], i});
		if(r[i] < m - 1) str.erase({x[i][r[i] + 1] + x[i][l[i]], i});
	};
	auto put = [&](int i) -> void {
		if(l[i]) stl.insert({x[i][r[i]] + x[i][l[i] - 1], i});
		if(r[i] < m - 1) str.insert({x[i][r[i] + 1] + x[i][l[i]], i});
	};
	for(int i = 0; i < n; i++){
		if(i < n / 2) l[i] = k, r[i] = m - 1;
		else l[i] = 0, r[i] = m - 1 - k;
		for(int j = 0; j < l[i]; j++) cost -= x[i][j];
		for(int j = r[i] + 1; j < m; j++) cost += x[i][j];
		put(i);
	}
	while(true){
		auto [a, b] = *prev(stl.end());
		auto [c, d] = *str.begin();
		if(b == d || a <= c) break;
		rid(b), rid(d);
		// swap(ans[b][l[b] - 1], ans[b][r[b]]);
		// swap(ans[d][l[d]], ans[d][r[d] + 1]);
		l[b] --, r[b] --;
		l[d] ++, r[d] ++;
		put(b), put(d);
	}
	vector<int> cnt(k);
	for(int i = 0; i < n; i++){
		priority_queue<pll, vector<pll>, greater<pll>> q;
		for(int j = 0; j < k; j++) q.push({cnt[j], j});
		set<int> used;
		for(int j = 0; j < l[i]; j++){
			auto [c, val] = q.top(); q.pop();
			cnt[val] ++;
			ans[i][j] = val, used.insert(val);
		}
		int c = 0;
		for(int j = r[i] + 1; j < m; j++){
			while(used.count(c)) c++;
			ans[i][j] = c;
			c++;
		}
		while(used.count(c)) c++;
		assert(c == k);
	}
	int mn = 1e9, mx = 0;
	cost = 0;
	vector<vector<int>> a(k);
	for(int i = 0; i < n; i++){
		for(int j = 0; j < l[i]; j++) cost -= x[i][j], mx = max(mx, x[i][j]);
		for(int j = r[i] + 1; j < m; j++) cost += x[i][j], mn = min(mn, x[i][j]);
	}
	// cout<<mn<<" "<<mx<<"\n";
	assert(mn >= mx);
	allocate_tickets(ans);
	return cost;
}

• Subtask 1: 11 / 11
• Subtask 2: 16 / 16
• Subtask 3: 14 / 14
• Subtask 4: 14 / 14
• Subtask 5: 12 / 12
• Subtask 6: 23 / 23
• Subtask 7: 10 / 10