Submission #93322

#	Time	Username	Problem	Language	Result	Execution time	Memory
93322		toloraia	Bomb (IZhO17_bomb)	C++14	34 / 100	1099 ms	57752 KiB

bomb

#include <bits/stdc++.h>
#define ll long long
#define F first
#define S second
#pragma GCC ("O3")
using namespace std;
 
const int N = 2600;
 
 
 
int n, m;
char ch[N][N];
int A[N][N], B[N][N];
 
int main()
{
    ios::sync_with_stdio(false);
    cin>>n>>m;
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= m; j++)
            cin>>ch[i][j];
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= m; j++)
            A[i][j] = A[i - 1][j] + A[i][j - 1] - A[i - 1][j - 1] + ch[i][j] - '0';
    int J = m;
    int ans = 0;
    for (int I = 1; I <= n && I * J >= ans; I++){
        while (J){
            bool ok = 1;
            for (int i = 0; i <= n; i++)
                for (int j = 0; j <= m; j++)
                    B[i][j] = 0;
            for (int i = 0; i + I <= n; i++)
                for (int j = 0; j + J <= m; j++){
                    int x = A[i + I][j + J] - A[i + I][j] - A[i][j + J] + A[i][j];
                    if (x == I * J){
                        B[i + I + 1][j + J + 1]++;
                        B[i + 1][j + J + 1]--;
                        B[i + I + 1][j + 1]--;
                        B[i + 1][j + 1]++;
                    }
                }
            for (int i = 1; i <= n; i++)
                for (int j = 1; j <= m; j++)
                    B[i][j] += B[i - 1][j] + B[i][j - 1] - B[i - 1][j - 1];
            for (int i = 1; i <= n; i++)
                for (int j = 1; j <= m; j++)
                    if (ch[i][j] == '1' && B[i][j] == 0)
                        ok = 0;
            if (ok)
                break;
            J--;
        }
        ans = max (ans, I * J);
    }
    cout<<ans<<endl;
    return 0;
}

Compilation message (stderr)

bomb.cpp:5:0: warning: ignoring #pragma GCC  [-Wunknown-pragmas]
 #pragma GCC ("O3")

• Subtask 1: 34 / 100