Submission #140505

# Submission time Handle Problem Language Result Execution time Memory
140505 2019-08-03T09:10:04 Z wasyl Snake Escaping (JOI18_snake_escaping) C++11
0 / 100
3 ms 504 KB
#include <bits/stdc++.h>
using namespace std;

constexpr int lax = 20, qax = 1e6, nax = (1 << lax);

int l, q, n, tab[nax], pre[3][nax];
string s;
vector< int > ind;

int id(const char c)
{
    if (c == '?') return 2;
    return c - '0';
}

int rek(const int t, string& s, const int v)
{
    for (int j = v; j < ind.size(); ++j)
    {
        int i = ind[j];
        if (id(s[i]) == t)
        {
            int res = 0;
            if (t == 2)
            {
                s[i] = '0';
                res += rek(t, s, i + 1);
                s[i] = '1';
                res += rek(t, s, i + 1);
                s[i] = '?';
                return res;
            }
            if (t == 0)
            {
                s[i] = '?';
                res += rek(t, s, i + 1);
                s[i] = '1';
                res -= rek(t, s, i + 1);
                s[i] = '0';
                return res;
            }
            if (t == 1)
            {
                s[i] = '?';
                res += rek(t, s, i + 1);
                s[i] = '0';
                res -= rek(t, s, i + 1);
                s[i] = '1';
                return res;
            }

        }
    }
    int msk = 0;
    for (int i = 0; i < l; ++i)
    {
        if (s[i] == '0') continue;
        if (s[i] == '1' and t == 2)
            msk += (1 << i);
        if (s[i] == '?')
            msk += (1 << i);
    }
    //cerr << s << ' ' << msk << ' ' << pre[t][msk] << '\n';
    return pre[t][msk]; //spo
}

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    cin >> l >> q;
    n = (1 << l);

    cin >> s;

    for (int i = 0; i < n; ++i)
        tab[i] = s[i] - '0';

    for (int i = 0; i < n; ++i)
        pre[0][i] = tab[(n - 1) - i];
    for (int i = 0; i < n; ++i)
        pre[1][i] = tab[i];
    for (int i = 0; i < n; ++i)
        pre[2][i] = tab[i];

    for (int i = 0; i < l; ++i)
        for (int j = 0; j < n; ++j)
            if ((1 << i) & j)
                pre[0][j] += pre[0][j - (1 << i)],
                pre[1][j] += pre[1][j - (1 << i)];

                for (int i = 0; i < q; ++i)
                {
                    string s; cin >> s;
                    reverse(begin(s), end(s));
                    int zl[2] = {0, 0};
                    for (char c : s)
                        if (c == '0' or c == '1')
                            ++zl[c - '0'];
                    if (zl[0] <= lax / 3)
                    {
                        ind.clear();
                        for (int i = 0; i < l; ++i)
                            if (s[i] == '0')
                                ind.push_back(i);
                        cout << rek(0, s, 0) << '\n';
                    }
                    else if (zl[1] <= lax / 3)
                    {
                        ind.clear();
                        for (int i = 0; i < l; ++i)
                            if (s[i] == '1')
                                ind.push_back(i);
                        cout << rek(1, s, 0) << '\n';
                    }
                    else if (l - zl[0] - zl[1] <= lax / 3)
                    {
                        ind.clear();
                        for (int i = 0; i < l; ++i)
                            if (s[i] == '?')
                                ind.push_back(i);
                        cout << rek(2, s, 0) << '\n';
                    }
                }
}

Compilation message

snake_escaping.cpp: In function 'int rek(int, std::__cxx11::string&, int)':
snake_escaping.cpp:18:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int j = v; j < ind.size(); ++j)
                     ~~^~~~~~~~~~~~
snake_escaping.cpp: In function 'int main()':
snake_escaping.cpp:89:13: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
             if ((1 << i) & j)
             ^~
snake_escaping.cpp:93:17: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
                 for (int i = 0; i < q; ++i)
                 ^~~
# Verdict Execution time Memory Grader output
1 Correct 2 ms 504 KB Output is correct
2 Incorrect 3 ms 376 KB Output isn't correct
3 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 2 ms 504 KB Output is correct
2 Incorrect 3 ms 376 KB Output isn't correct
3 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 2 ms 504 KB Output is correct
2 Incorrect 3 ms 376 KB Output isn't correct
3 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 2 ms 504 KB Output is correct
2 Incorrect 3 ms 376 KB Output isn't correct
3 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 2 ms 504 KB Output is correct
2 Incorrect 3 ms 376 KB Output isn't correct
3 Halted 0 ms 0 KB -