oj.uz

Submission #173828

# Submission time Handle Problem Language Result Execution time Memory
173828 2020-01-05T13:34:09 Z emil_physmath Red-blue table (IZhO19_stones) C++17
100 / 100
 250 ms 2476 KB 
#include <algorithm>
#include <iostream>
#include <vector>
#include <string>
using namespace std;

void SwapMN(vector<string>& a)
{
    int n = a.size(), m = a[0].length();
    for (int i = 0; i < n; ++i)
        for (int j = 0; j < m; ++j)
            a[i][j] = (a[i][j] == '-' ? '+' : '-');
    swap(n, m);
    vector<string> temp(n, string(m, '-'));
    for (int i = 0; i < n; ++i)
        for (int j = 0; j < m; ++j)
            temp[i][j] = a[j][i];
    a.swap(temp);
}
int Value(const vector<string>& a)
{
    int n = a.size();
    int m = a[0].length();
    int res = 0;
    for (int i = 0; i < n; ++i)
        if (2 * count(a[i].begin(), a[i].end(), '+') > m)
            ++res;
    for (int j = 0; j < m; ++j)
    {
        int cnt = 0;
        for (int i = 0; i < n; ++i)
            if (a[i][j] == '-')
                ++cnt;
        if (2 * cnt > n)
            ++res;
    }
    return res;
}
bool Solve(int n, int nx, int m, int mx, bool swapMN)
{
    if (nx < 0 || mx < 0 || nx > n || mx > m) return false;
    if (swapMN)
    {
        swap(n, m);
        swap(nx, mx);
    }
    vector<string> a(n, string(m, '-'));
    for (int i = n - nx; i < n; ++i)
        for (int j = 0; j < m; ++j)
            a[i][j] = '-';
    for (int i = 0; i < n; ++i)
        for (int j = m - mx; j < m; ++j)
            a[i][j] = '+';
    int block = ((m + 2) / 2 - mx);
    int j = m - mx - 1;
    if (mx < m)
        for (int i = 0; i < n - nx; ++i)
        {
            for (int cnt = 0; cnt < block; ++cnt)
                a[i][(j - cnt + m - mx) % (m - mx)] = '+';
            j = (j - block + m - mx) % (m - mx);
        }
    if (swapMN)
    {
        swap(n, m);
        swap(nx, mx);
        SwapMN(a);
    }
    int value = Value(a);
    if (value < n + m - nx - mx)
        return false;
    cout << value << '\n';
    for (int i = 0; i < n; ++i)
        cout << a[i] << '\n';
    cout << flush;
    return true;
}
int main()
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    int t;
    cin >> t;
    while (t--)
    {
        int n, m;
        cin >> n >> m;
        bool printed = false;
        for (int sum = 0; !printed && sum <= 4; ++sum)
            for (int i = 0; !printed && i <= 4; ++i)
                if (Solve(n, i, m, sum - i, false) || Solve(n, i, m, sum - i, true))
                {
                    printed = true;
                    break;
                }
    }
}

Subtask #1
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 376 KB Output is correct

Subtask #3
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 6 ms 376 KB Output is correct
4 Correct 10 ms 376 KB Output is correct

Subtask #4
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 84 ms 1400 KB Output is correct
2 Correct 83 ms 1744 KB Output is correct
3 Correct 63 ms 2016 KB Output is correct

Subtask #5
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 132 ms 1400 KB Output is correct
2 Correct 97 ms 1664 KB Output is correct
3 Correct 95 ms 1500 KB Output is correct

Subtask #6
31.0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 6 ms 376 KB Output is correct
4 Correct 10 ms 376 KB Output is correct
5 Correct 84 ms 1400 KB Output is correct
6 Correct 83 ms 1744 KB Output is correct
7 Correct 63 ms 2016 KB Output is correct
8 Correct 132 ms 1400 KB Output is correct
9 Correct 97 ms 1664 KB Output is correct
10 Correct 95 ms 1500 KB Output is correct
11 Correct 42 ms 556 KB Output is correct
12 Correct 58 ms 1668 KB Output is correct
13 Correct 71 ms 1556 KB Output is correct
14 Correct 65 ms 1320 KB Output is correct
15 Correct 250 ms 2476 KB Output is correct
16 Correct 193 ms 2060 KB Output is correct
17 Correct 44 ms 1072 KB Output is correct