Submission #756727

#	Time	Username	Problem	Language	Result	Execution time	Memory
756727		boris_mihov	Mechanical Doll (IOI18_doll)	C++17	37 / 100	112 ms	12968 KiB

doll

#include <algorithm>
#include <iostream>
#include <cassert>
#include <numeric>
#include <vector>
#include "doll.h"

typedef long long llong;
const int MAXN = 1000000 + 10;
const int MAXS = 1000000 + 10;
const int INF  = 1e9;

int n, m, cnt;
int prefix[MAXN];
std::vector <int> a, x, y, c;
int perm[MAXN];
int treeRoot;

void rec(int l, int r, int root)
{
    assert(l != r);
    if (prefix[r + 1] - prefix[l] == 0)
    {
        x[root - 1] = -root;
        y[root - 1] = -treeRoot;
        return;
    }

    if (l + 1 == r)
    {
        if (perm[l] < a.size()) y[root - 1] = a[perm[l]];
        else y[root - 1] = -treeRoot;

        if (perm[r] < a.size()) x[root - 1] = a[perm[r]];
        else x[root - 1] = -treeRoot;
        return;
    }

    int mid = (l + r) / 2;
    x.push_back(-INF);
    x.push_back(-INF);
    y.push_back(-INF);
    y.push_back(-INF);
    cnt += 2;

    y[root - 1] = -(cnt - 1);
    x[root - 1] = -cnt;
    rec(l, mid, -y[root - 1]);
    rec(mid + 1, r, -x[root - 1]);
}

int reversed(int x, int bits)
{
    int res = 0;
    for (int i = 0 ; i < bits ; ++i)
    {
        if (x & (1 << i))
        {
            res |= (1 << bits - 1 - i);
        }
    }

    return res;
}

void create_circuit(int M, std::vector <int> A)
{
    a.clear(); x.clear(); y.clear(); c.clear();
    m = M; n = A.size(); A.push_back(0); a = A;
    c.resize(m + 1);

    if (a.size() == 1)
    {
        c[a[0]] = 0;
    } else
    {
        for (int i = 0 ; i <= m ; ++i)
        {
            c[i] = -1;
        }

        int sz = 1, bits = 0;
        while (sz < a.size())
        {
            sz <<= 1;
            bits++;
        }

        x.push_back(-INF);
        y.push_back(-INF);
        std::reverse(a.begin(), a.end());
        std::iota(perm, perm + sz, 0);
        
        for (int i = 0 ; i < sz ; ++i)
        {
            int rev = reversed(i, bits);
            if (perm[i] > perm[rev])
            {
                std::swap(perm[i], perm[rev]);
            }
        }

        for (int i = 0 ; i < sz ; ++i)
        {
            prefix[i + 1] = prefix[i] + (perm[i] < a.size());
        }

        cnt++;
        treeRoot = cnt;
        rec(0, sz - 1, cnt);
    }

    answer(c, x, y);
}

Compilation message (stderr)

doll.cpp: In function 'void rec(int, int, int)':
doll.cpp:31:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   31 |         if (perm[l] < a.size()) y[root - 1] = a[perm[l]];
      |             ~~~~~~~~^~~~~~~~~~
doll.cpp:34:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   34 |         if (perm[r] < a.size()) x[root - 1] = a[perm[r]];
      |             ~~~~~~~~^~~~~~~~~~
doll.cpp: In function 'int reversed(int, int)':
doll.cpp:59:35: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
   59 |             res |= (1 << bits - 1 - i);
      |                          ~~~~~~~~~^~~
doll.cpp: In function 'void create_circuit(int, std::vector<int>)':
doll.cpp:83:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   83 |         while (sz < a.size())
      |                ~~~^~~~~~~~~~
doll.cpp:105:50: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  105 |             prefix[i + 1] = prefix[i] + (perm[i] < a.size());
      |                                          ~~~~~~~~^~~~~~~~~~

• Subtask 1: 0 / 2
• Subtask 2: 0 / 4
• Subtask 3: 0 / 10
• Subtask 4: 0 / 10
• Subtask 5: 9 / 18
• Subtask 6: 28 / 56