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Submission #833895

# Submission time Handle Problem Language Result Execution time Memory
833895 2023-08-22T09:23:53 Z vjudge1 Bomb (IZhO17_bomb) C++14
91 / 100
 647 ms 75232 KB 
#include<bits/stdc++.h>
using namespace std;

const int MAX = 2500 + 5;

int n,m,x[MAX][MAX],pf[MAX][MAX],atk[MAX][MAX];
char c;

int get(int x1,int y1,int x2,int y2){
	x1--, y1--;
	return pf[x2][y2] - pf[x2][y1] - pf[x1][y2] + pf[x1][y1];
}

bool bisa(int h,int w){
	memset(atk, 0, sizeof atk);
	for(int i = h; i<=n; i++){
		for(int j = w; j<=m; j++){
			if(get(i-h+1, j-w+1, i, j) == h*w){
				atk[i-h+1][j-w+1]++;
				atk[i-h+1][j+1]--;
				atk[i+1][j-w+1]--;
				atk[i+1][j+1]++;
			}
		}
	}
	for(int i = 1; i<=n; i++){
		for(int j = 1; j<=m; j++){
			atk[i][j] = atk[i-1][j] + atk[i][j-1] - atk[i-1][j-1] + atk[i][j];
			if(atk[i][j]){
				if(!x[i][j])return false;
			}
			else {
				if(x[i][j])return false;
			}
		}
	}
	return true;
}

int main(){
	ios_base::sync_with_stdio(false);
	cin>>n>>m;
	
	for(int i = 1; i<=n; i++){
		for(int j = 1; j<=m; j++){
			cin>>c;
			x[i][j] = (c=='1');
			pf[i][j] = pf[i-1][j] + pf[i][j-1] - pf[i-1][j-1] + x[i][j];
		}
	}
	
//	bisa(3, 1);
//	
//	for(int i = 1; i<=n; i++){
//		for(int j = 1; j<=m; j++){
//			cout<<atk[i][j]<<" ";
//		}
//		cout<<endl;
//	}
	
	int ans = 0;
	int w,h;
	
	int le,ri,mid,s;
	le = 2, ri = min(n,m);
	s = 1;
	while(le<=ri){
		mid = (le+ri)>>1;
		if(bisa(mid, mid))s = mid, le = mid+1;
		else ri = mid-1;
	}
	
	h = w = s;
	if(w+1<=m && bisa(h,w+1)){
		le = w+1, ri = m;
		while(le<=ri){
			mid = (le+ri)>>1;
			if(bisa(h, mid))w = mid, le = mid+1;
			else ri = mid-1;
		}
	}
	else if(h+1<=n){
		le = h+1, ri = n;
		while(le<=ri){
			mid = (le+ri)>>1;
			if(bisa(mid, w))h = mid, le = mid+1;
			else ri = mid-1;
		}
	}
	
	cout<<h*w<<endl;
	return 0;
}

Compilation message

bomb.cpp: In function 'int main()':
bomb.cpp:61:6: warning: unused variable 'ans' [-Wunused-variable]
   61 |  int ans = 0;
      |      ^~~

Subtask #1
91.0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 24788 KB Output is correct
2 Correct 16 ms 25044 KB Output is correct
3 Correct 40 ms 44948 KB Output is correct
4 Correct 37 ms 44976 KB Output is correct
5 Correct 31 ms 24908 KB Output is correct
6 Correct 31 ms 24788 KB Output is correct
7 Correct 18 ms 24916 KB Output is correct
8 Correct 25 ms 25044 KB Output is correct
9 Correct 25 ms 25044 KB Output is correct
10 Correct 23 ms 24976 KB Output is correct
11 Correct 25 ms 25052 KB Output is correct
12 Correct 24 ms 24916 KB Output is correct
13 Correct 22 ms 24916 KB Output is correct
14 Correct 23 ms 24996 KB Output is correct
15 Correct 26 ms 24952 KB Output is correct
16 Correct 27 ms 25044 KB Output is correct
17 Correct 33 ms 25452 KB Output is correct
18 Correct 33 ms 25472 KB Output is correct
19 Correct 33 ms 25684 KB Output is correct
20 Correct 33 ms 25684 KB Output is correct
21 Correct 33 ms 25324 KB Output is correct
22 Correct 36 ms 25536 KB Output is correct
23 Correct 36 ms 25768 KB Output is correct
24 Correct 36 ms 25556 KB Output is correct
25 Correct 36 ms 25684 KB Output is correct
26 Correct 36 ms 25776 KB Output is correct
27 Correct 46 ms 27860 KB Output is correct
28 Correct 47 ms 27988 KB Output is correct
29 Incorrect 51 ms 28968 KB Output isn't correct
30 Correct 59 ms 29800 KB Output is correct
31 Correct 51 ms 28628 KB Output is correct
32 Correct 54 ms 29356 KB Output is correct
33 Correct 66 ms 30076 KB Output is correct
34 Correct 52 ms 28372 KB Output is correct
35 Correct 59 ms 29960 KB Output is correct
36 Correct 60 ms 30036 KB Output is correct
37 Incorrect 26 ms 25052 KB Output isn't correct
38 Correct 342 ms 74572 KB Output is correct
39 Correct 25 ms 25052 KB Output is correct
40 Incorrect 111 ms 37844 KB Output isn't correct
41 Incorrect 27 ms 25044 KB Output isn't correct
42 Incorrect 35 ms 25772 KB Output isn't correct
43 Correct 492 ms 74740 KB Output is correct
44 Incorrect 58 ms 30036 KB Output isn't correct
45 Incorrect 390 ms 74724 KB Output isn't correct
46 Correct 325 ms 74668 KB Output is correct
47 Incorrect 537 ms 74812 KB Output isn't correct
48 Correct 428 ms 74772 KB Output is correct
49 Correct 398 ms 74664 KB Output is correct
50 Correct 456 ms 74772 KB Output is correct
51 Correct 490 ms 74844 KB Output is correct
52 Correct 561 ms 74928 KB Output is correct
53 Correct 513 ms 74832 KB Output is correct
54 Correct 459 ms 74728 KB Output is correct
55 Correct 483 ms 74864 KB Output is correct
56 Correct 467 ms 74896 KB Output is correct
57 Correct 572 ms 74764 KB Output is correct
58 Correct 527 ms 74904 KB Output is correct
59 Correct 597 ms 75012 KB Output is correct
60 Correct 436 ms 75024 KB Output is correct
61 Correct 487 ms 75028 KB Output is correct
62 Correct 552 ms 74864 KB Output is correct
63 Correct 410 ms 74972 KB Output is correct
64 Correct 367 ms 75024 KB Output is correct
65 Correct 492 ms 74848 KB Output is correct
66 Correct 399 ms 74732 KB Output is correct
67 Correct 561 ms 74796 KB Output is correct
68 Correct 607 ms 75028 KB Output is correct
69 Correct 647 ms 75080 KB Output is correct
70 Correct 335 ms 65184 KB Output is correct
71 Correct 448 ms 74836 KB Output is correct
72 Correct 504 ms 75144 KB Output is correct
73 Correct 503 ms 75084 KB Output is correct
74 Correct 624 ms 75124 KB Output is correct
75 Correct 514 ms 75120 KB Output is correct
76 Correct 524 ms 75108 KB Output is correct
77 Correct 542 ms 75120 KB Output is correct
78 Correct 622 ms 75164 KB Output is correct
79 Correct 378 ms 75164 KB Output is correct
80 Correct 369 ms 75144 KB Output is correct
81 Correct 473 ms 75108 KB Output is correct
82 Correct 494 ms 75160 KB Output is correct
83 Correct 570 ms 75164 KB Output is correct
84 Correct 365 ms 75156 KB Output is correct
85 Correct 578 ms 75088 KB Output is correct
86 Correct 462 ms 75160 KB Output is correct
87 Incorrect 505 ms 75156 KB Output isn't correct
88 Correct 586 ms 75164 KB Output is correct
89 Correct 512 ms 75160 KB Output is correct
90 Correct 370 ms 65232 KB Output is correct
91 Correct 555 ms 75160 KB Output is correct
92 Correct 498 ms 75160 KB Output is correct
93 Correct 463 ms 75116 KB Output is correct
94 Correct 564 ms 75164 KB Output is correct
95 Correct 557 ms 75232 KB Output is correct
96 Correct 574 ms 75136 KB Output is correct
97 Correct 556 ms 75192 KB Output is correct
98 Correct 619 ms 75160 KB Output is correct
99 Correct 483 ms 75160 KB Output is correct
100 Correct 444 ms 75052 KB Output is correct