Submission #796791

#	Time	Username	Problem	Language	Result	Execution time	Memory
796791		SlavicG	Minerals (JOI19_minerals)	C++17	100 / 100	58 ms	6428 KiB

minerals

#include <bits/stdc++.h>
#include "minerals.h"
using namespace std;
 
#define sz(a) (int)a.size()
mt19937 rng(69);
//b - valoarea elementului, stateul (aprins/stins)
int ans = 0, prevans = -1;
const int N = 1e5 + 69;
int in[N], added[N];
map<pair<int, int>, int> cant_be;

void rec(vector<int> a, vector<pair<int, int>> b, int offset) {
    if(b.empty() || a.empty()) return;
    if(sz(b) == 1) {
        for(auto x: a) Answer(x, b[0].first);
        return;
    }
    vector<int> first_half, second_half;
    int mid = (sz(b) < 10 ? sz(b) / 2 : min(sz(b) - 1, (int)(sz(b) * 0.369)));
    vector<pair<int, int>> left, right;
    for(auto& x: a) {
        if(added[x]) continue;
        if(in[x] <= mid + offset) {
            first_half.push_back(x);
            x = -1;
        }
        else added[x] = 1;
    }

    for(int i = 0; i < sz(b); ++i) {
        if(i < mid) left.push_back(b[i]);
        else right.push_back(b[i]);
    }
    int offset2 = offset + sz(left);
    {
        int change1 = 0, change2 = 0;
        for(auto& x: left) {
            if(!x.second) {
                ++change1;
            } else {
                ++change2;
            }
        }
        for(auto& x: right) {
            if(x.second) {
                ++change1;
            } else {
                ++change2;
            }
        }
        if(change2 < change1) swap(left, right), swap(first_half, second_half), swap(offset, offset2);
    }
 
    for(auto& x: left) {
        if(!x.second) {
            prevans = Query(x.first);
            x.second = 1;
        }
    }
    for(auto& x: right) {
        if(x.second) {
            prevans = Query(x.first);
            x.second = 0;
        }
    }
 
    shuffle(a.begin(), a.end(), rng);
    for(auto x: a) {
        if(x == -1) continue;
        if(sz(second_half) >= sz(right)) {
            first_half.push_back(x);
            continue;
        }
        if(sz(first_half) >= sz(left)) {
            second_half.push_back(x);
            continue;
        }
        int ans = Query(x);
        if(ans == prevans) {
            first_half.push_back(x);
        } else {
            second_half.push_back(x);
        }
        prevans = ans;
    }
    rec(second_half, right, offset2);
    rec(first_half, left, offset);
}
 
void Solve(int n) {
    for(int i = 0; i < N; ++i) in[i] = INT_MAX;
    vector<int> p1, p2;
    vector<int> bulanea(2 * n);
    iota(bulanea.begin(), bulanea.end(), 1);
    shuffle(bulanea.begin(), bulanea.end(), rng);
    for(int i: bulanea) {
        ans = Query(i);
        if(ans == prevans) {
            p2.push_back(i);
            in[i] = ans;
        } else {
            p1.push_back(i);
        }
        prevans = ans;
        if(sz(p1) == n) {
            for(int j = 0; j < sz(bulanea); ++j) {
                if(bulanea[j] == i) {
                    for(int f = j + 1; f < sz(bulanea); ++f) {
                        p2.push_back(bulanea[f]);
                    }
                    break;
                }
            }
            break;
        }
    }
    assert(sz(p1) == n && sz(p2) == n);
    vector<pair<int, int>> b;
    for(auto x: p1) b.push_back({x, 1});
    rec(p2, b, 0);
}
/*
4
1 5
2 6
3 4
7 8
*/
// g++ -Wall -lm -static -DEVAL -o minerals -O2 minerals.cpp grader.cpp -std=c++17

• Subtask 1: 6 / 6
• Subtask 2: 25 / 25
• Subtask 3: 9 / 9
• Subtask 4: 30 / 30
• Subtask 5: 5 / 5
• Subtask 6: 5 / 5
• Subtask 7: 5 / 5
• Subtask 8: 5 / 5
• Subtask 9: 10 / 10