Submission #697263

# Submission time Handle Problem Language Result Execution time Memory
697263 2023-02-09T01:33:25 Z allllekssssa Bomb (IZhO17_bomb) C++14
51 / 100
1000 ms 76752 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 = 1; 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);
       }
    }


    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 30436 KB Output is correct
4 Correct 13 ms 30404 KB Output is correct
5 Correct 0 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 1 ms 468 KB Output is correct
10 Correct 1 ms 468 KB Output is correct
11 Correct 1 ms 468 KB Output is correct
12 Correct 1 ms 468 KB Output is correct
13 Correct 1 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 1108 KB Output is correct
18 Correct 3 ms 1108 KB Output is correct
19 Correct 5 ms 1492 KB Output is correct
20 Correct 6 ms 1520 KB Output is correct
21 Correct 3 ms 980 KB Output is correct
22 Correct 5 ms 1236 KB Output is correct
23 Correct 9 ms 1620 KB Output is correct
24 Correct 5 ms 1364 KB Output is correct
25 Correct 13 ms 1620 KB Output is correct
26 Correct 11 ms 1628 KB Output is correct
27 Correct 131 ms 4692 KB Output is correct
28 Correct 248 ms 5076 KB Output is correct
29 Correct 357 ms 6452 KB Output is correct
30 Correct 655 ms 7704 KB Output is correct
31 Correct 519 ms 6100 KB Output is correct
32 Correct 481 ms 7000 KB Output is correct
33 Correct 801 ms 8100 KB Output is correct
34 Correct 126 ms 5524 KB Output is correct
35 Correct 549 ms 8092 KB Output is correct
36 Correct 665 ms 8088 KB Output is correct
37 Correct 1 ms 468 KB Output is correct
38 Correct 267 ms 76628 KB Output is correct
39 Correct 1 ms 468 KB Output is correct
40 Incorrect 34 ms 19796 KB Output isn't correct
41 Correct 1 ms 468 KB Output is correct
42 Correct 11 ms 1636 KB Output is correct
43 Correct 300 ms 76588 KB Output is correct
44 Correct 939 ms 8088 KB Output is correct
45 Execution timed out 1089 ms 76600 KB Time limit exceeded
46 Correct 294 ms 76540 KB Output is correct
47 Execution timed out 1090 ms 76580 KB Time limit exceeded
48 Execution timed out 1096 ms 76748 KB Time limit exceeded
49 Correct 270 ms 76684 KB Output is correct
50 Execution timed out 1091 ms 76676 KB Time limit exceeded
51 Execution timed out 1095 ms 76620 KB Time limit exceeded
52 Execution timed out 1086 ms 76628 KB Time limit exceeded
53 Execution timed out 1092 ms 76640 KB Time limit exceeded
54 Execution timed out 1087 ms 76752 KB Time limit exceeded
55 Execution timed out 1081 ms 76696 KB Time limit exceeded
56 Correct 268 ms 76636 KB Output is correct
57 Execution timed out 1091 ms 76568 KB Time limit exceeded
58 Execution timed out 1075 ms 76620 KB Time limit exceeded
59 Execution timed out 1091 ms 76620 KB Time limit exceeded
60 Correct 269 ms 76632 KB Output is correct
61 Correct 277 ms 76636 KB Output is correct
62 Correct 278 ms 76556 KB Output is correct
63 Correct 269 ms 76636 KB Output is correct
64 Correct 273 ms 76632 KB Output is correct
65 Execution timed out 1090 ms 76536 KB Time limit exceeded
66 Incorrect 403 ms 76600 KB Output isn't correct
67 Execution timed out 1091 ms 76620 KB Time limit exceeded
68 Execution timed out 1091 ms 76572 KB Time limit exceeded
69 Execution timed out 1088 ms 76636 KB Time limit exceeded
70 Incorrect 192 ms 61360 KB Output isn't correct
71 Incorrect 278 ms 76648 KB Output isn't correct
72 Incorrect 263 ms 76632 KB Output isn't correct
73 Incorrect 265 ms 76584 KB Output isn't correct
74 Incorrect 269 ms 76748 KB Output isn't correct
75 Incorrect 262 ms 76528 KB Output isn't correct
76 Incorrect 269 ms 76528 KB Output isn't correct
77 Incorrect 272 ms 76660 KB Output isn't correct
78 Incorrect 265 ms 76540 KB Output isn't correct
79 Incorrect 272 ms 76632 KB Output isn't correct
80 Incorrect 268 ms 76700 KB Output isn't correct
81 Incorrect 271 ms 76588 KB Output isn't correct
82 Incorrect 270 ms 76524 KB Output isn't correct
83 Incorrect 273 ms 76620 KB Output isn't correct
84 Incorrect 258 ms 76636 KB Output isn't correct
85 Incorrect 273 ms 76560 KB Output isn't correct
86 Incorrect 285 ms 76632 KB Output isn't correct
87 Incorrect 267 ms 76512 KB Output isn't correct
88 Incorrect 265 ms 76584 KB Output isn't correct
89 Incorrect 266 ms 76532 KB Output isn't correct
90 Incorrect 179 ms 61444 KB Output isn't correct
91 Incorrect 273 ms 76532 KB Output isn't correct
92 Incorrect 261 ms 76636 KB Output isn't correct
93 Incorrect 262 ms 76752 KB Output isn't correct
94 Incorrect 264 ms 76728 KB Output isn't correct
95 Incorrect 281 ms 76624 KB Output isn't correct
96 Incorrect 291 ms 76632 KB Output isn't correct
97 Incorrect 264 ms 76532 KB Output isn't correct
98 Incorrect 264 ms 76572 KB Output isn't correct
99 Incorrect 264 ms 76600 KB Output isn't correct
100 Incorrect 265 ms 76556 KB Output isn't correct