Submission #938833

#	Time	Username	Problem	Language	Result	Execution time	Memory
938833		Alcabel	Unscrambling a Messy Bug (IOI16_messy)	C++17	100 / 100	1 ms	856 KiB

messy

#include <bits/stdc++.h>
#include "messy.h"
using namespace std;

string query;

void rec_build(int l, int r) {
    if (r - l <= 1) { return; }
    int m = l + (r - l) / 2;
    for (int i = m; i < r; ++i) {
        query[i] = '1';
        add_element(query);
        query[i] = '0';
    }
    for (int i = l; i < m; ++i) {
        query[i] = '1';
    }
    rec_build(m, r);
    for (int i = l; i < m; ++i) {
        query[i] = '0';
    }
    for (int i = m; i < r; ++i) {
        query[i] = '1';
    }
    rec_build(l, m);
    for (int i = m; i < r; ++i) {
        query[i] = '0';
    }
}

void rec_find(vector<int>& rest, int bit, vector<int>& p) {
    if ((int)rest.size() <= 1) { return; }
    /*cerr << "rest:\n";
    for (const int& i : rest) {
        cerr << i << ' ';
    }
    cerr << "\nbit: " << bit << '\n';*/
    assert(bit >= 0);
    vector<int> on, off;
    for (const int& i : rest) {
        query[i] = '1';
        if (check_element(query)) {
            p[i] |= (1 << bit);
            on.emplace_back(i);
        } else {
            off.emplace_back(i);
        }
        query[i] = '0';
    }
    for (const int& i : off) {
        query[i] = '1';
    }
    rec_find(on, bit - 1, p);
    for (const int& i : off) {
        query[i] = '0';
    }
    for (const int& i : on) {
        query[i] = '1';
    }
    rec_find(off, bit - 1, p);
    for (const int& i : on) {
        query[i] = '0';
    }
}

vector<int> restore_permutation(int n, int w, int r) {
    vector<int> p(n);
    query = string(n, '0');
    rec_build(0, n);
    compile_set();
    int lg = 0;
    while ((1 << lg) < n) {
        ++lg;
    }
    vector<int> rest(n);
    iota(rest.begin(), rest.end(), 0);
    rec_find(rest, lg - 1, p);
    return p;
}

• Subtask 1: 20 / 20
• Subtask 2: 18 / 18
• Subtask 3: 11 / 11
• Subtask 4: 21 / 21
• Subtask 5: 30 / 30