Submission #1162980

#	Time	Username	Problem	Language	Result	Execution time	Memory
1162980		SmuggingSpun	Red-blue table (IZhO19_stones)	C++20	43 / 100	11 ms	328 KiB

stones

#include<bits/stdc++.h>
#define taskname "A"
using namespace std;
template<class T>bool maximize(T& a, T b){
    if(a < b){
        a = b;
        return true;
    }
    return false;
}
int n, m;
namespace sub1{
    void solve(){
        vector<vector<char>>best;
        int opt = 0;
        for(int mask = (1 << (n * m)) - 1; mask > -1; mask--){
            vector<vector<char>>state(n, vector<char>(m));
            int cur_opt = 0;
            for(int i = 0, p = 0; i < n; i++){
                int cnt = 0;
                for(int j = 0; j < m; j++, p++){
                    cnt += int((state[i][j] = ((1 << p & mask) ? '+' : '-')) == '+'); 
                }
                if(cnt > (m >> 1)){
                    cur_opt++;
                }
            }
            for(int j = 0; j < m; j++){
                int cnt = 0;
                for(int i = 0; i < n; i++){
                    cnt += int(state[i][j] == '-');
                }
                if(cnt > (n >> 1)){
                    cur_opt++;
                }
            }
            if(maximize(opt, cur_opt)){
                best = state;
            }
        }
        cout << opt << "\n";
        for(int i = 0; i < n; i++){
            for(int j = 0; j < m; j++){
                cout << best[i][j];
            }
            cout << "\n";
        }
    }
}
namespace sub2{
    void solve(){
        if(n == 1){
            cout << m << "\n" << string(m, '-') << "\n";
        }
        else if(m == 1){
            cout << n << "\n";
            for(int i = 0; i < n; i++){
                cout << "+\n";
            }
        }
        else if(n == 2){
            cout << m << "\n" << string(m, '-') << "\n" << string(m, '-') << "\n";
        }
        else if(m == 2){
            cout << n << "\n";
            for(int i = 0; i < n; i++){
                cout << "++\n";
            }
        }
        else if(n == 3){
            cout << m + 1 << "\n" << string(m, '-') << "\n" << string(m, '-') << " " << string(m, '+') << "\n";
        }
        else{
            cout << n + 1 << "\n";
            for(int i = 0; i < n; i++){
                cout << "+-+\n";
            }
        }
    }
}
namespace sub3{
    void solve(){
        if(n == 4){
            cout << m + 1 << "\n" << string(m, '-') << "\n" << string(m, '-') << "\n" << string(m, '-') << "\n" << string(m, '+') << "\n";
        }
        else if(m == 4){
            cout << n + 1 << "\n";
            for(int i = 0; i < n; i++){
                cout << "+++-\n";
            }
        }
        else if(n == 5){
            vector<vector<char>>ans(n, vector<char>(m, '-'));
            for(int i = 0; i <= (m >> 1); i++){
                ans[0][i] = ans[1][m - i - 1] = '+';
            }
            for(int i = 0; i < m; i++){
                if(ans[0][i] != '+' || ans[1][i] != '+'){
                    ans[2][i] = '+';
                }
            }
            int cnt = m;
            for(int i = 0; i < 3; i++){
                if(count(ans[i].begin(), ans[i].end(), '+') > (m >> 1)){
                    cnt++;
                }
            }
            cout << cnt << "\n";
            for(int i = 0; i < n; i++){
                for(int j = 0; j < m; j++){
                    cout << ans[i][j];
                }
                cout << "\n";
            }
        }
        else{   
            vector<vector<char>>ans(n, vector<char>(m, '+'));
            for(int i = 0; i <= (n >> 1); i++){
                ans[i][0] = ans[n - i - 1][1] = '-';
            }
            for(int i = 0; i < n; i++){
                if(ans[i][0] != '-' || ans[i][1] != '-'){
                    ans[i][2] = '-';
                }
            }
            int cnt = n;
            for(int j = 0; j < 3; j++){
                int cnt_sub = 0;
                for(int i = 0; i < n; i++){
                    cnt_sub += int(ans[i][j] == '-');
                }
                if(cnt_sub > (n >> 1)){
                    cnt++;
                }
            }
            cout << cnt << "\n";
            for(int i = 0; i < n; i++){
                for(int j = 0; j < m; j++){
                    cout << ans[i][j];
                }
                cout << "\n";
            }
        }
    }
}
int main(){
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    if(fopen(taskname".inp", "r")){
        freopen(taskname".inp", "r", stdin);
    }
    int _t;
    cin >> _t;
    for(int _ = 0; _ < _t; _++){
        cin >> n >> m;
        if(_t <= 16 && n * m <= 16){
            sub1::solve();
        }
        else if(min(n, m) <= 3){
            sub2::solve();
        }
        else if(min(n, m) <= 5){
            sub3::solve();
        }
    }
}

Compilation message (stderr)

stones.cpp: In function 'int main()':
stones.cpp:149:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  149 |         freopen(taskname".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 17 / 17
• Subtask 2: 10 / 10
• Subtask 3: 16 / 16
• Subtask 4: 0 / 11
• Subtask 5: 0 / 15
• Subtask 6: 0 / 31