Submission #711171

#	Time	Username	Problem	Language	Result	Execution time	Memory
711171		onlk97	Red-blue table (IZhO19_stones)	C++14	100 / 100	31 ms	2232 KiB

stones

#include <bits/stdc++.h>
using namespace std;
void solve(){
    int n,m;
    cin>>n>>m;
    int ans1=-1,rr;
    for (int r=0; r<=n; r++){
        int cnt=r,req=n/2+1-(n-r);
        if (req<=0) cnt+=m;
        else {
            int L=0,R=m;
            while (L<R){
                int mid=(L+R+1)/2;
                if (r*min(mid,m-m/2-1)>=mid*req) L=mid;
                else R=mid-1; 
            }
            cnt+=L;
        }
        if (cnt>ans1){
            ans1=cnt;
            rr=r;
        }
    }
    cout<<ans1<<'\n';
    int tt=ans1-rr;
    char op[n+1][m+1];
    for (int i=1; i<=n; i++){
        for (int j=1; j<=m; j++) op[i][j]=(i<=rr?'+':'-');
    }
    if (n-rr<n/2+1){
        int ut=min(ans1-rr,m-m/2-1);
        for (int j=1; j<=rr; j++){
            for (int k=(j-1)*ut; k<j*ut; k++) op[j][k%(ans1-rr)+1]='-';
        }
    }
    for (int i=1; i<=n; i++){
        for (int j=1; j<=m; j++) cout<<op[i][j];
        cout<<'\n';
    }
}
signed main(){
    ios_base::sync_with_stdio(0); cin.tie(0);
    int t;
    cin>>t;
    while (t--) solve();
}

Compilation message (stderr)

stones.cpp: In function 'void solve()':
stones.cpp:25:9: warning: unused variable 'tt' [-Wunused-variable]
   25 |     int tt=ans1-rr;
      |         ^~
stones.cpp:6:17: warning: 'rr' may be used uninitialized in this function [-Wmaybe-uninitialized]
    6 |     int ans1=-1,rr;
      |                 ^~

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