Submission #697264

# Submission time Handle Problem Language Result Execution time Memory
697264 2023-02-09T01:35:18 Z allllekssssa Bomb (IZhO17_bomb) C++14
51 / 100
1000 ms 76876 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);
       }
    }


    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 30412 KB Output is correct
4 Correct 14 ms 30364 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 0 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 1 ms 468 KB Output is correct
12 Correct 1 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 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 1492 KB Output is correct
21 Correct 4 ms 980 KB Output is correct
22 Correct 5 ms 1312 KB Output is correct
23 Correct 8 ms 1620 KB Output is correct
24 Correct 5 ms 1364 KB Output is correct
25 Correct 9 ms 1620 KB Output is correct
26 Correct 8 ms 1620 KB Output is correct
27 Correct 127 ms 4772 KB Output is correct
28 Correct 256 ms 5076 KB Output is correct
29 Correct 321 ms 6356 KB Output is correct
30 Correct 639 ms 7692 KB Output is correct
31 Correct 472 ms 6080 KB Output is correct
32 Correct 475 ms 6996 KB Output is correct
33 Correct 761 ms 8088 KB Output is correct
34 Correct 115 ms 5528 KB Output is correct
35 Correct 557 ms 8088 KB Output is correct
36 Correct 670 ms 8084 KB Output is correct
37 Correct 1 ms 468 KB Output is correct
38 Correct 284 ms 76516 KB Output is correct
39 Correct 1 ms 468 KB Output is correct
40 Incorrect 35 ms 19860 KB Output isn't correct
41 Correct 1 ms 468 KB Output is correct
42 Correct 11 ms 1632 KB Output is correct
43 Correct 307 ms 76528 KB Output is correct
44 Correct 929 ms 8088 KB Output is correct
45 Execution timed out 1087 ms 76532 KB Time limit exceeded
46 Correct 276 ms 76632 KB Output is correct
47 Execution timed out 1091 ms 76528 KB Time limit exceeded
48 Execution timed out 1083 ms 76732 KB Time limit exceeded
49 Correct 285 ms 76620 KB Output is correct
50 Execution timed out 1084 ms 76632 KB Time limit exceeded
51 Execution timed out 1082 ms 76624 KB Time limit exceeded
52 Execution timed out 1088 ms 76636 KB Time limit exceeded
53 Execution timed out 1091 ms 76548 KB Time limit exceeded
54 Execution timed out 1092 ms 76744 KB Time limit exceeded
55 Execution timed out 1094 ms 76616 KB Time limit exceeded
56 Correct 281 ms 76876 KB Output is correct
57 Execution timed out 1088 ms 76516 KB Time limit exceeded
58 Execution timed out 1085 ms 76556 KB Time limit exceeded
59 Execution timed out 1085 ms 76720 KB Time limit exceeded
60 Correct 281 ms 76528 KB Output is correct
61 Correct 285 ms 76564 KB Output is correct
62 Correct 279 ms 76520 KB Output is correct
63 Correct 290 ms 76644 KB Output is correct
64 Correct 264 ms 76620 KB Output is correct
65 Execution timed out 1084 ms 76628 KB Time limit exceeded
66 Incorrect 399 ms 76640 KB Output isn't correct
67 Execution timed out 1094 ms 76556 KB Time limit exceeded
68 Execution timed out 1098 ms 76628 KB Time limit exceeded
69 Execution timed out 1094 ms 76568 KB Time limit exceeded
70 Incorrect 177 ms 61364 KB Output isn't correct
71 Incorrect 272 ms 76620 KB Output isn't correct
72 Incorrect 278 ms 76632 KB Output isn't correct
73 Incorrect 302 ms 76536 KB Output isn't correct
74 Incorrect 269 ms 76596 KB Output isn't correct
75 Incorrect 282 ms 76596 KB Output isn't correct
76 Incorrect 270 ms 76532 KB Output isn't correct
77 Incorrect 271 ms 76660 KB Output isn't correct
78 Incorrect 270 ms 76528 KB Output isn't correct
79 Incorrect 272 ms 76596 KB Output isn't correct
80 Incorrect 281 ms 76628 KB Output isn't correct
81 Incorrect 275 ms 76620 KB Output isn't correct
82 Incorrect 274 ms 76656 KB Output isn't correct
83 Incorrect 274 ms 76628 KB Output isn't correct
84 Incorrect 272 ms 76648 KB Output isn't correct
85 Incorrect 284 ms 76636 KB Output isn't correct
86 Incorrect 269 ms 76612 KB Output isn't correct
87 Incorrect 277 ms 76560 KB Output isn't correct
88 Incorrect 273 ms 76752 KB Output isn't correct
89 Incorrect 272 ms 76536 KB Output isn't correct
90 Incorrect 191 ms 61364 KB Output isn't correct
91 Incorrect 283 ms 76724 KB Output isn't correct
92 Incorrect 281 ms 76536 KB Output isn't correct
93 Incorrect 283 ms 76628 KB Output isn't correct
94 Incorrect 276 ms 76636 KB Output isn't correct
95 Incorrect 269 ms 76536 KB Output isn't correct
96 Incorrect 272 ms 76636 KB Output isn't correct
97 Incorrect 280 ms 76516 KB Output isn't correct
98 Incorrect 278 ms 76672 KB Output isn't correct
99 Incorrect 278 ms 76620 KB Output isn't correct
100 Incorrect 271 ms 76620 KB Output isn't correct