Submission #431807

#	Time	Username	Problem	Language	Result	Execution time	Memory
431807		JeanBombeur	Jousting tournament (IOI12_tournament)	C++17	49 / 100	26 ms	2372 KiB

tournament

#include <iostream>
#include <cstdio>
#include <vector>
using namespace std;
 
//    <|°_°|>
 
const int INFINI = (1000 * 1000 * 1000);
const int MAX_CHEVALIERS = (100 * 1000);
const int LOG = (16);
 
int NbVictoires[MAX_CHEVALIERS];
int Rang[MAX_CHEVALIERS];
 
int Next[MAX_CHEVALIERS];
 
int Fenwick[MAX_CHEVALIERS];
 
int FindNext(int a) {
    if (Rang[Next[a]] >= 0)
        return Next[a];
    return Next[a] = FindNext(Next[a]);
}
 
void Add(int id, int val) {
    for (int i = id; i < MAX_CHEVALIERS; i |= (i + 1))
    {
        Fenwick[i] += val;
    }
    return;
}
 
int FindFirst(int nb) {
    int ans = -1;
    int sum = 0;
    for (int i = (1 << LOG); i > 0; i >>= 1)
    {
        if (ans + i < MAX_CHEVALIERS && sum + Fenwick[ans + i] < nb)
        {
            ans += i;
            sum += Fenwick[ans];
        }
    }
    return ans + 1;
}
 
int GetBestPosition(int nbChevaliers, int nbRounds, int nouvRang, int *Ranks, int *Left, int *Right) {
 
    for (int i = 0; i < nbChevaliers; i ++)
    {
        Next[i] = i + 1;
        Rang[i] = Ranks[i];
        NbVictoires[i] = 0;
        Fenwick[i] = 1;
    }
    
    for (int i = 0; i < MAX_CHEVALIERS; i ++)
    {
        if (i | (i + 1) < MAX_CHEVALIERS)
            Fenwick[i | (i + 1)] += Fenwick[i];
    }
    
    pair <int, int> ans = {0, 0};
    
    for (int i = 0; i < nbRounds; i ++)
    {
        Left[i] ++, Right[i] ++;
        vector <int> pos;
        
        int first = FindFirst(Left[i]);
        
        for (int c = Left[i]; c <= Right[i]; c ++)
        {
            pos.push_back(first);
            first = FindNext(first);
        }
        
        int maxRang = -1;
        pair <int, int> maxDP = {- INFINI - 1, 0};
        
        for (int a : pos)
        {
            if (a != pos.back())
                maxRang = max(maxRang, Rang[a]);
            if (NbVictoires[a] > maxDP.first)
                maxDP = {NbVictoires[a], a};
        }
        
        maxDP.first ++;
        
        if (maxRang > nouvRang)
            maxDP.first = - INFINI;
        
        Rang[maxDP.second] = max(maxRang, Rang[pos.back()]);
        NbVictoires[maxDP.second] = maxDP.first;
        
        for (int a : pos)
        {
            if (a != maxDP.second)
            {
                Rang[a] = -1;
                Add(a, -1);
                NbVictoires[a] = - INFINI;
            }
        }
        
        if (maxDP.first > ans.first || (maxDP.first == ans.first && maxDP.second < ans.second))
        {
            ans = make_pair(maxDP.first, maxDP.second);
        }
    }
    return ans.second;
}

Compilation message (stderr)

tournament.cpp: In function 'int GetBestPosition(int, int, int, int*, int*, int*)':
tournament.cpp:59:25: warning: suggest parentheses around comparison in operand of '|' [-Wparentheses]
   59 |         if (i | (i + 1) < MAX_CHEVALIERS)
      |                 ~~~~~~~~^~~~~~~~~~~~~~~~

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