Submission #154516

#	Time	Username	Problem	Language	Result	Execution time	Memory
154516		Pankin	Red-blue table (IZhO19_stones)	C++14	100 / 100	80 ms	1680 KiB

stones

#include <bits/stdc++.h>

/*
#pragma GCC optimize("unroll-loops")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("-O3")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
*/

#define mp make_pair
#define ll long long
#define ld long double
#define pb push_back
#define fast_io ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define fs first
#define sc second
#define getfiles ifstream cin("input.txt"); ofstream cout("output.txt");
#define endl '\n'
#define con continue
#define pii pair<int, int>
#define all(x) x.begin(), x.end()

const int INF = 2000000005;
const ll BIG_INF = 2000000000000000005;
const int mod = 1000000007;
const int P = 31;
const ld PI = 3.141592653589793238462643;
const double eps = 1e-9;

using namespace std;

vector< pair<int, int> > dir = {
    {
        -1, 0
    },
    {
        0, 1
    },
    {
        1, 0
    },
    {
        0, -1
    }
};

bool valid(int x, int y, int n, int m) {
    return x >= 0 && y >= 0 && x < n && y < m;
}

mt19937 rng(1999999973);

inline int getAns(vector<vector<bool>> &a) {
    int ans = 0;
    for (int i = 0; i < a.size(); i++) {
        int diff = 0;
        for (int j = 0; j < a[0].size(); j++) {
            if (a[i][j])
                diff++;
            else
                diff--;
        }
        if (diff > 0)
            ans++;
    }
    for (int j = 0; j < a[0].size(); j++) {
        int diff = 0;
        for (int i = 0; i < a.size(); i++) {
            if (a[i][j])
                diff--;
            else
                diff++;
        }
        if (diff > 0)
            ans++;
    }
    return ans;
}

vector< vector<bool> > solve(int n, int m) {
    vector< vector<bool> > a(n, vector<bool>(m, true));
    int mxad = (m + 1) / 2 - 1, req = n - ((n + 1) / 2 - 1);
    priority_queue<pii> q;
    for (int i = 0; i < n; i++)
        q.push(mp(mxad, i));
    int cur_column = m - 1;
    while(true) {
        vector<pii> cur;
        cur.reserve(req);
        bool good = true;
        for (int i = 0; i < req; i++) {
            pii v = q.top();
            if (v.fs == 0) {
                good = false;
                break;
            }
            cur.pb(v);
            q.pop();
        }
        if (!good)
            break;
        for (int i = 0; i < req; i++) {
            a[cur[i].sc][cur_column] = false;
            q.push(mp(cur[i].fs - 1, cur[i].sc));
        }

        cur_column--;
    }
    return a;
}

signed main() {
    fast_io;

    int tests;
    cin >> tests;
    while(tests--) {
        int n, m;
        cin >> n >> m;
        vector<vector<bool>> a(n, vector<bool>(m, true));

        if (n >= m)
            a = solve(n, m);
        else {
            vector< vector<bool> > b(m, vector<bool>(n, true));
            b = solve(m, n);
            for (int i = 0; i < n; i++) {
                for (int j = 0; j < m; j++) {
                    a[i][j] = !b[j][i];
                }
            }
        }

        cout << getAns(a) << endl;
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < m; j++) {
                cout << (a[i][j] ? '+' : '-');
            }
            cout << endl;
        }
    }

    return 0;
}

Compilation message (stderr)

stones.cpp: In function 'int getAns(std::vector<std::vector<bool> >&)':
stones.cpp:55:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < a.size(); i++) {
                     ~~^~~~~~~~~~
stones.cpp:57:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (int j = 0; j < a[0].size(); j++) {
                         ~~^~~~~~~~~~~~~
stones.cpp:66:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int j = 0; j < a[0].size(); j++) {
                     ~~^~~~~~~~~~~~~
stones.cpp:68:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (int i = 0; i < a.size(); i++) {
                         ~~^~~~~~~~~~

• Subtask 1: 17 / 17
• Subtask 2: 10 / 10
• Subtask 3: 16 / 16
• Subtask 4: 11 / 11
• Subtask 5: 15 / 15
• Subtask 6: 31 / 31