Submission #697266

# Submission time Handle Problem Language Result Execution time Memory
697266 2023-02-09T01:47:16 Z allllekssssa Bomb (IZhO17_bomb) C++14
51 / 100
1000 ms 76768 KB
#include<bits/stdc++.h>
 
using namespace std;


#define pii pair<int ,int>
#define pb push_back

const int maxN = 2600;
int n, m;
int a[maxN][maxN];
int d[maxN][maxN];
int c[maxN][maxN];
string s;
int cnt[maxN];

int getDSum(int x1, int y1, int x2, int y2) {
	if (x2 > n || y2 > m) return 0;
	return d[x2][y2] + d[x1 - 1][y1 - 1] - d[x1 - 1][y2] - d[x2][y1 - 1];
}
 
int getCSum(int x1, int y1, int x2, int y2) {
	x1 = max(x1, 1);
	y1 = max(y1, 1);
	return c[x2][y2] + c[x1 - 1][y1 - 1] - c[x1 - 1][y2] - c[x2][y1 - 1];
}
 
bool check(int x, int y) {
 
	for (int i = 1; i<=n; i++) {
		for (int j = 1; j<=m; j++) {
			c[i][j] = 0;
		}
	}
   
   for (int i = 1; i<=n; i++) {
   	 for (int j = 1; j<=m; j++) {
   	 	if (getDSum(i, j, i + x - 1, j + y - 1) == x * y) c[i][j] = 1;
   	 }
   }
 
   for (int i = 1; i <= n; i++) {
		for (int j = 1; j<=m; j++) {
			c[i][j] += c[i - 1][j] + c[i][j - 1] - c[i - 1][j - 1];
		}
	}
 
   for (int i = 1; i<=n; i++) {
   	for (int j = 1; j <= m; j++) {
 		  if (a[i][j] && getCSum(i - x + 1, j - y + 1, i, j) == 0) return false;
   	  }
   }
 
   return true;
}

int heuristic1() {
    
	vector<pii> gornji;

	for (int i = 1; i<=n; i++) {
		for (int j = 1; j<=m; j++) {
			if (a[i - 1][j] == 0 && a[i][j - 1] == 0 && a[i][j] == 1) gornji.pb({i, j});
		}
	}

	// random_shuffle(gornji.begin(), gornji.end());
    
    for (int i = 1; i <=n; i++) {
    	cnt[i] = m;
    }

      for (int i = 0; i < min(2700, (int) gornji.size()); i++) {
       for (int len = 1; len <= n; len++) {
          
          int width = m;
          int x = gornji[i].first;
          int y = gornji[i].second;


          while (width > 0 && getDSum(x, y, x + len - 1, y + width - 1) != len * width) width--;
       	  cnt[len] = min(cnt[len], width);
       }
    }

     
     for (int i = gornji.size() - 1; i > max((int) gornji.size() - 2000, 0); i--) {
       for (int len = 1; len <= n; len++) {
          
          int width = m;
          int x = gornji[i].first;
          int y = gornji[i].second;


          while (width > 0 && getDSum(x, y, x + len - 1, y + width - 1) != len * width) width--;
       	  cnt[len] = min(cnt[len], width);
       }
    }


    int ans = 0;
    for (int i = 1; i<=n; i++) {
    	ans = max(ans, i * cnt[i]);
    }

    return ans;
}
 
int heuristic() {
  
   int minW = n;
   int minH = m;

	for (int i = 1; i<=n; i++) {
		int cur = 0;
		for (int j = 1; j<=m; j++) {
			if (a[i][j] == 1) cur++; else {
				if (cur > 0) {
					minH = min(minH, cur);
					cur = 0;
				}
			}
		}

	   if (cur > 0) minH = min(minH, cur);
	}

	for (int j = 1; j<=m; j++) {
		int cur = 0;
		for (int i = 1; i<=n; i++) {
			if (a[i][j] == 1) cur++; else {
				if (cur > 0) {
					minW = min(minW, cur);
					cur = 0;
				}
			}
		}

		if (cur > 0) minW = min(minW, cur);
	}
    
    int ans = minW * minH;
    if (!check(minW, minH)) return heuristic1();
	return ans;
}

int main() {
 
	cin >> n >> m;
 
	for (int i = 1; i <=n; i++) {
		cin >> s;
 
		for (int j = 0; j < m; j++) {
			a[i][j + 1] = s[j] - '0';
		}
	}
    
    for (int i = 1; i <= n; i++) {
		for (int j = 1; j<=m; j++) {
			d[i][j] = d[i - 1][j] + d[i][j - 1] + a[i][j] - d[i - 1][j - 1];
		}
	}
   
	if (n > 450 || m > 450) {
		cout << heuristic() << endl;
		return 0;
	}

   
    int ans = 0;
    
    int width = m;
	for (int i = 1; i <=n; i++) {
 
		while (width > 0 && !check(i, width)) width--;
 
		ans = max(ans, i * width);
	}
    
    cout << ans << endl;
}
# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 1 ms 468 KB Output is correct
3 Correct 13 ms 30408 KB Output is correct
4 Correct 13 ms 30420 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 0 ms 340 KB Output is correct
7 Correct 0 ms 340 KB Output is correct
8 Correct 1 ms 468 KB Output is correct
9 Correct 0 ms 468 KB Output is correct
10 Correct 0 ms 468 KB Output is correct
11 Correct 0 ms 468 KB Output is correct
12 Correct 0 ms 468 KB Output is correct
13 Correct 0 ms 468 KB Output is correct
14 Correct 1 ms 468 KB Output is correct
15 Correct 1 ms 468 KB Output is correct
16 Correct 1 ms 468 KB Output is correct
17 Correct 3 ms 1160 KB Output is correct
18 Correct 3 ms 1108 KB Output is correct
19 Correct 6 ms 1492 KB Output is correct
20 Correct 7 ms 1492 KB Output is correct
21 Correct 5 ms 980 KB Output is correct
22 Correct 5 ms 1236 KB Output is correct
23 Correct 11 ms 1748 KB Output is correct
24 Correct 4 ms 1364 KB Output is correct
25 Correct 10 ms 1620 KB Output is correct
26 Correct 8 ms 1620 KB Output is correct
27 Correct 124 ms 4768 KB Output is correct
28 Correct 246 ms 5076 KB Output is correct
29 Correct 332 ms 6448 KB Output is correct
30 Correct 616 ms 7692 KB Output is correct
31 Correct 469 ms 6080 KB Output is correct
32 Correct 466 ms 6996 KB Output is correct
33 Correct 758 ms 8084 KB Output is correct
34 Correct 119 ms 5520 KB Output is correct
35 Correct 548 ms 8088 KB Output is correct
36 Correct 657 ms 8088 KB Output is correct
37 Correct 0 ms 468 KB Output is correct
38 Correct 268 ms 76632 KB Output is correct
39 Correct 0 ms 468 KB Output is correct
40 Incorrect 40 ms 19768 KB Output isn't correct
41 Correct 1 ms 468 KB Output is correct
42 Correct 11 ms 1620 KB Output is correct
43 Correct 265 ms 76580 KB Output is correct
44 Correct 957 ms 8100 KB Output is correct
45 Execution timed out 1092 ms 76632 KB Time limit exceeded
46 Correct 268 ms 76768 KB Output is correct
47 Execution timed out 1090 ms 76532 KB Time limit exceeded
48 Execution timed out 1096 ms 76620 KB Time limit exceeded
49 Correct 274 ms 76648 KB Output is correct
50 Execution timed out 1096 ms 76640 KB Time limit exceeded
51 Execution timed out 1085 ms 76652 KB Time limit exceeded
52 Execution timed out 1095 ms 76512 KB Time limit exceeded
53 Execution timed out 1090 ms 76680 KB Time limit exceeded
54 Execution timed out 1049 ms 76620 KB Time limit exceeded
55 Execution timed out 1089 ms 76636 KB Time limit exceeded
56 Correct 268 ms 76656 KB Output is correct
57 Execution timed out 1084 ms 76696 KB Time limit exceeded
58 Execution timed out 1090 ms 76628 KB Time limit exceeded
59 Execution timed out 1095 ms 76620 KB Time limit exceeded
60 Correct 261 ms 76604 KB Output is correct
61 Correct 292 ms 76672 KB Output is correct
62 Correct 265 ms 76624 KB Output is correct
63 Correct 274 ms 76632 KB Output is correct
64 Correct 259 ms 76616 KB Output is correct
65 Execution timed out 1096 ms 76616 KB Time limit exceeded
66 Incorrect 791 ms 76724 KB Output isn't correct
67 Execution timed out 1095 ms 76524 KB Time limit exceeded
68 Execution timed out 1085 ms 76604 KB Time limit exceeded
69 Execution timed out 1096 ms 76628 KB Time limit exceeded
70 Incorrect 180 ms 61264 KB Output isn't correct
71 Incorrect 272 ms 76536 KB Output isn't correct
72 Incorrect 248 ms 76580 KB Output isn't correct
73 Incorrect 277 ms 76636 KB Output isn't correct
74 Incorrect 273 ms 76616 KB Output isn't correct
75 Incorrect 277 ms 76756 KB Output isn't correct
76 Incorrect 268 ms 76620 KB Output isn't correct
77 Incorrect 269 ms 76724 KB Output isn't correct
78 Incorrect 278 ms 76628 KB Output isn't correct
79 Incorrect 271 ms 76636 KB Output isn't correct
80 Incorrect 282 ms 76620 KB Output isn't correct
81 Incorrect 277 ms 76532 KB Output isn't correct
82 Incorrect 300 ms 76708 KB Output isn't correct
83 Incorrect 275 ms 76528 KB Output isn't correct
84 Incorrect 283 ms 76628 KB Output isn't correct
85 Incorrect 294 ms 76640 KB Output isn't correct
86 Incorrect 289 ms 76532 KB Output isn't correct
87 Incorrect 293 ms 76636 KB Output isn't correct
88 Incorrect 279 ms 76536 KB Output isn't correct
89 Incorrect 289 ms 76636 KB Output isn't correct
90 Incorrect 198 ms 61364 KB Output isn't correct
91 Incorrect 304 ms 76640 KB Output isn't correct
92 Incorrect 288 ms 76576 KB Output isn't correct
93 Incorrect 280 ms 76708 KB Output isn't correct
94 Incorrect 292 ms 76600 KB Output isn't correct
95 Incorrect 272 ms 76536 KB Output isn't correct
96 Incorrect 277 ms 76632 KB Output isn't correct
97 Incorrect 273 ms 76632 KB Output isn't correct
98 Incorrect 285 ms 76628 KB Output isn't correct
99 Incorrect 285 ms 76748 KB Output isn't correct
100 Incorrect 277 ms 76636 KB Output isn't correct