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Submission #697253

# Submission time Handle Problem Language Result Execution time Memory
697253 2023-02-09T01:20:56 Z allllekssssa Bomb (IZhO17_bomb) C++14
21 / 100
 1000 ms 78424 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(400, (int) gornji.size()); i++) {
       for (int len = 1; len <= n; len++) {
          
          int x = gornji[i].first;
          int y = gornji[i].second;

       	  int lo = -1;
       	  int ro = m + 1;
 
       	  while(lo < ro - 1) {
       	  	 int mid = lo + ro >> 1;
       	  	 if (getDSum(x, y, x + len - 1, y + mid - 1) == len * mid) lo = mid; else ro = mid;
       	  }

       	  cnt[len] = min(cnt[len], lo);
       }
    }


    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;
}

Compilation message

bomb.cpp: In function 'int heuristic1()':
bomb.cpp:83:26: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   83 |             int mid = lo + ro >> 1;
      |                       ~~~^~~~

Subtask #1
21.0 / 100.0

# 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 18 ms 30352 KB Output is correct
4 Correct 20 ms 30448 KB Output is correct
5 Correct 38 ms 340 KB Output is correct
6 Correct 6 ms 340 KB Output is correct
7 Correct 0 ms 340 KB Output is correct
8 Incorrect 1 ms 468 KB Output isn't correct
9 Incorrect 1 ms 468 KB Output isn't correct
10 Correct 0 ms 468 KB Output is correct
11 Incorrect 1 ms 468 KB Output isn't correct
12 Incorrect 1 ms 468 KB Output isn't correct
13 Correct 1 ms 468 KB Output is correct
14 Correct 0 ms 468 KB Output is correct
15 Incorrect 1 ms 468 KB Output isn't correct
16 Correct 1 ms 468 KB Output is correct
17 Correct 1 ms 1108 KB Output is correct
18 Correct 1 ms 1108 KB Output is correct
19 Incorrect 1 ms 1492 KB Output isn't correct
20 Incorrect 1 ms 1492 KB Output isn't correct
21 Correct 1 ms 980 KB Output is correct
22 Correct 2 ms 1236 KB Output is correct
23 Incorrect 1 ms 1620 KB Output isn't correct
24 Incorrect 1 ms 1364 KB Output isn't correct
25 Incorrect 1 ms 1620 KB Output isn't correct
26 Correct 1 ms 1620 KB Output is correct
27 Correct 5 ms 4692 KB Output is correct
28 Incorrect 6 ms 5076 KB Output isn't correct
29 Incorrect 7 ms 6484 KB Output isn't correct
30 Incorrect 10 ms 7724 KB Output isn't correct
31 Incorrect 7 ms 6100 KB Output isn't correct
32 Incorrect 8 ms 6996 KB Output isn't correct
33 Incorrect 10 ms 8020 KB Output isn't correct
34 Incorrect 5 ms 5476 KB Output isn't correct
35 Incorrect 11 ms 8020 KB Output isn't correct
36 Correct 10 ms 8108 KB Output is correct
37 Incorrect 1 ms 468 KB Output isn't correct
38 Execution timed out 1090 ms 76576 KB Time limit exceeded
39 Incorrect 0 ms 468 KB Output isn't correct
40 Execution timed out 1095 ms 19836 KB Time limit exceeded
41 Correct 1 ms 468 KB Output is correct
42 Correct 2 ms 1620 KB Output is correct
43 Execution timed out 1087 ms 76516 KB Time limit exceeded
44 Correct 14 ms 8020 KB Output is correct
45 Execution timed out 1096 ms 76592 KB Time limit exceeded
46 Execution timed out 1083 ms 76616 KB Time limit exceeded
47 Execution timed out 1089 ms 76560 KB Time limit exceeded
48 Execution timed out 1098 ms 76540 KB Time limit exceeded
49 Execution timed out 1084 ms 76532 KB Time limit exceeded
50 Execution timed out 1090 ms 76612 KB Time limit exceeded
51 Execution timed out 1051 ms 76644 KB Time limit exceeded
52 Execution timed out 1093 ms 76520 KB Time limit exceeded
53 Execution timed out 1093 ms 76528 KB Time limit exceeded
54 Execution timed out 1093 ms 76576 KB Time limit exceeded
55 Execution timed out 1076 ms 76636 KB Time limit exceeded
56 Execution timed out 1061 ms 76620 KB Time limit exceeded
57 Execution timed out 1100 ms 76624 KB Time limit exceeded
58 Execution timed out 1093 ms 76568 KB Time limit exceeded
59 Execution timed out 1096 ms 76620 KB Time limit exceeded
60 Execution timed out 1097 ms 76528 KB Time limit exceeded
61 Execution timed out 1101 ms 76548 KB Time limit exceeded
62 Execution timed out 1103 ms 76552 KB Time limit exceeded
63 Execution timed out 1071 ms 76552 KB Time limit exceeded
64 Execution timed out 1104 ms 76560 KB Time limit exceeded
65 Execution timed out 1084 ms 76540 KB Time limit exceeded
66 Execution timed out 1089 ms 76576 KB Time limit exceeded
67 Execution timed out 1026 ms 76588 KB Time limit exceeded
68 Execution timed out 1087 ms 76528 KB Time limit exceeded
69 Execution timed out 1091 ms 76556 KB Time limit exceeded
70 Execution timed out 1094 ms 61304 KB Time limit exceeded
71 Execution timed out 1091 ms 76600 KB Time limit exceeded
72 Execution timed out 1104 ms 76512 KB Time limit exceeded
73 Execution timed out 1074 ms 76624 KB Time limit exceeded
74 Execution timed out 1081 ms 77456 KB Time limit exceeded
75 Execution timed out 1103 ms 78212 KB Time limit exceeded
76 Execution timed out 1079 ms 78184 KB Time limit exceeded
77 Execution timed out 1080 ms 78176 KB Time limit exceeded
78 Execution timed out 1069 ms 78396 KB Time limit exceeded
79 Execution timed out 1045 ms 78152 KB Time limit exceeded
80 Execution timed out 1022 ms 78280 KB Time limit exceeded
81 Execution timed out 1094 ms 78300 KB Time limit exceeded
82 Execution timed out 1025 ms 78416 KB Time limit exceeded
83 Execution timed out 1012 ms 78324 KB Time limit exceeded
84 Execution timed out 1104 ms 78352 KB Time limit exceeded
85 Execution timed out 1010 ms 78412 KB Time limit exceeded
86 Execution timed out 1044 ms 78304 KB Time limit exceeded
87 Execution timed out 1084 ms 78352 KB Time limit exceeded
88 Execution timed out 1105 ms 78424 KB Time limit exceeded
89 Execution timed out 1077 ms 78416 KB Time limit exceeded
90 Execution timed out 1060 ms 61248 KB Time limit exceeded
91 Execution timed out 1081 ms 76604 KB Time limit exceeded
92 Execution timed out 1079 ms 76612 KB Time limit exceeded
93 Execution timed out 1090 ms 76552 KB Time limit exceeded
94 Execution timed out 1079 ms 76560 KB Time limit exceeded
95 Execution timed out 1078 ms 76532 KB Time limit exceeded
96 Execution timed out 1084 ms 76512 KB Time limit exceeded
97 Execution timed out 1079 ms 76680 KB Time limit exceeded
98 Execution timed out 1088 ms 76580 KB Time limit exceeded
99 Execution timed out 1093 ms 76612 KB Time limit exceeded
100 Execution timed out 1091 ms 76508 KB Time limit exceeded