Submission #874233

#	Time	Username	Problem	Language	Result	Execution time	Memory
874233		Matjaz	Jousting tournament (IOI12_tournament)	C++14	49 / 100	1050 ms	2188 KiB

tournament

#include <vector>
#include <algorithm>
#include <iostream>

using namespace std;


// Insight: each S[i] E[i] corresponds to some interval in the original set of positions
// The interval only matters if your player is in it - and there is a unique answer as to whether it wins or loses
// You can find the best position with a sweep.


int GetBestPosition(int N, int C, int R, int *K, int *S, int *E) {
    
    vector<int> s(N+1);
    s[0] = 0;
    for (int i=1;i<=N;i++) s[i] = s[i-1] + (K[i-1] > R);
    
    vector<pair<int,int> > sweep_events;
    
    vector<pair<int,int> > positions(N);
    vector<pair<int,int> > intervals(C);
    for (int i=0;i<N;i++) positions[i] = make_pair(i,i);
    for (int i=0;i<C;i++){
        intervals[i] = make_pair(positions[S[i]].first, positions[E[i]].second);
        positions[S[i]] = intervals[i];
        for (int j=E[i]+1;j<N;j++) positions[S[i] + j - E[i]] = positions[j];
        if (s[intervals[i].second] - s[intervals[i].first] == 0){
            sweep_events.push_back(make_pair(intervals[i].first, 1));
            sweep_events.push_back(make_pair(intervals[i].second + 1, -1));
        }
    }
    
    sort(sweep_events.begin(), sweep_events.end());
    
    int best_position = 0;
    int best_wins = 0;
    int wins = 0;

    
    for (int i=0;i<sweep_events.size();i++){
        wins += sweep_events[i].second;
        if (wins > best_wins){
            best_wins = wins;
            best_position = sweep_events[i].first;
        }
    }
    
    
    return best_position;
}

Compilation message (stderr)

tournament.cpp: In function 'int GetBestPosition(int, int, int, int*, int*, int*)':
tournament.cpp:41:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   41 |     for (int i=0;i<sweep_events.size();i++){
      |                  ~^~~~~~~~~~~~~~~~~~~~

• Subtask 1: 17 / 17
• Subtask 2: 32 / 32
• Subtask 3: 0 / 51