Submission #1218343

#	Time	Username	Problem	Language	Result	Execution time	Memory
1218343		brinton	Carnival Tickets (IOI20_tickets)	C++20	62 / 100	2779 ms	2162688 KiB

tickets

#include "tickets.h"
#include <bits/stdc++.h>
using namespace std;
long long m_allocate_tickets(vector<vector<int>> answer,vector<vector<int>> x){
	allocate_tickets(answer);
	// find k;
	int N = answer.size();
	int k = 0;
	for(auto &i:answer[0]) k = max(i+1,k);
	vector<vector<int>> cards(k);
	for(int i = 0;i < N;i++){
		for(int j = 0;j < answer[0].size();j++){
			if(answer[i][j] != -1) cards[answer[i][j]].push_back(x[i][j]);
		}
	}
	long long ans = 0;
	for(auto v:cards) {
		sort(v.begin(),v.end());
		for(int i = 0;i < N;i++){
			if(i < N/2){
				ans -= v[i];
			}else{
				ans += v[i];
			}
		}
	}
	return ans;
}
#define inf (long long)(1e15)
long long find_maximum(int k, vector<vector<int>> x) {
	vector<vector<int>> cx = x;
	int N = x.size();
	int M = x[0].size();

	vector<vector<int>> backtrack(N,vector<int>(N*k/2+1));// dp[round][take+];

	vector<long long> dp(N*k/2+1,-inf);
	dp[0] = 0;
	for(int i = 0;i < N;i++){
		vector<long long> take(k+1);
		for(int j = 0;j < k;j++){
			take[0] -= x[i][j];
		}
		for(int j = 1;j <= k;j++){
			take[j] = take[j-1]+x[i][M-j]+x[i][k-j];
		}
		vector<long long> ndp(N*k/2+1);
		for(int j = 0;j <= N*k/2;j++){
			backtrack[i][j] = 0;
			ndp[j] = dp[j]+take[0];
			for(int tk = 1;tk <= k;tk++){
				if(j-tk < 0) break;
				if(dp[j-tk]+take[tk] > ndp[j]){
					ndp[j] = dp[j-tk]+take[tk];
					backtrack[i][j] = tk;
				}
			}
		}
		swap(dp,ndp);
	}
	vector<int> ones(N,0);
	x = vector<vector<int>>(N,vector<int>(M,0));
	{
		int cur = N*k/2;
		for(int i = N-1;i >= 0;i--){
			ones[i] = backtrack[i][cur];
			for(int d = 0;d < ones[i];d++){
				x[i][M-d-1] = 1;
			}
			cur -= backtrack[i][cur];
		}
	}
	// for(auto &i:ones) cout << i << " ";




	vector<vector<int>> answer(N,vector<int>(M,-1));
	vector<int> fpt(N,0);
	vector<int> bpt(N,M-1);

	

	for(int ck = 0;ck < k;ck++){
		// for(auto &i:ones) cout << i << " ";cout << endl;
		vector<pair<int,int>> colors;// cone,idx;
		for(int i = 0;i < N;i++){
			colors.push_back({ones[i],i});
		}
		sort(colors.begin(),colors.end());
		
		for(int i = 0;i < N;i++){
			// cout << type[i];
			auto [cone,cidx] = colors[i];
			if(i < N/2){// take zero
				answer[cidx][fpt[cidx]] = ck;
				ones[cidx] -= x[cidx][fpt[cidx]];
				fpt[cidx]++;
			}else{// take one
				answer[cidx][bpt[cidx]] = ck;
				ones[cidx] -= x[cidx][bpt[cidx]];
				bpt[cidx]--;
			}
		}
	}

	return m_allocate_tickets(answer,cx);
}

• Subtask 1: 11 / 11
• Subtask 2: 16 / 16
• Subtask 3: 0 / 14
• Subtask 4: 0 / 14
• Subtask 5: 12 / 12
• Subtask 6: 23 / 23
• Subtask 7: 0 / 10