Submission #334568

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
334568	2020-12-09T12:31:57 Z	tengiz05	Bomb (IZhO17_bomb)	C++17	100 / 100	326 ms	87660 KB

bomb

#include <bits/stdc++.h>
using namespace std;
//#define int long long
#define FASTIO ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
#define all(x) (x).begin(), (x).end()
#define pb push_back
#define pii pair<int, int>
#define ff first
#define ss second
#define PI acos(-1)
#define ld long double
const int mod = 1e9+7, N = 2505;
int msb(int val){return sizeof(int)*8-__builtin_clzll(val);}
int a[N][N], n, m, k;
bool usedup[N][N], usedr[N][N];
int up[N][N], down[N][N];
int ans[N];
vector<int> v[N];
vector<int> s[N];
void solve(int test_case){
	int i, j;
	cin >> n >> m;
	for(i=1;i<=n;i++){
		for(j=1;j<=m;j++){
			char c;
			cin >> c;
			a[i][j] = (c-'0');
		}
	}
	int mx=mod, my=mod;
	for(i=1;i<=n;i++){
		for(j=1;j<=m;j++){
			if(a[i][j] == 1){
				if(usedup[i][j])continue;
				int t = j;
				int tmp = 0;
				while(t <= m && a[i][t] == 1){
					tmp++;
					usedup[i][t] = true;
					t++;
				}mx = min(mx, tmp);
			}
		}
	}
	for(i=1;i<=n;i++){
		for(j=1;j<=m;j++){
			if(a[i][j] == 1){
				if(usedr[i][j])continue;
				int t = i;
				int tmp = 0;
				while(t <= n && a[t][j] == 1){
					tmp++;
					usedr[t][j] = true;
					t++;
				}my = min(my, tmp);
			}
		}
	}
	if(mx == mod){
		mx = 0;
		my = 0;
	}
	
	/// (mx, my) is greedy answer
	for(i=1;i<=n;i++){
		for(j=1;j<=m;j++){
			if(a[i][j])up[i][j] = up[i-1][j]+a[i][j];
		}
	}
	for(i=n;i>=1;i--){
		for(j=1;j<=m;j++){
			if(a[i][j])down[i][j] = down[i+1][j]+a[i][j];
		}
	}
	
	for(i=1;i<=n;i++){
		for(j=1;j<=m;j++){
			if(!a[i][j])continue;
			int cnt = 1;
			int tmp = j;
			while(j+1 <= m && a[i][j+1])cnt++,j++;
			v[i].pb(tmp);
			s[i].pb(cnt);
		}
	}
	for(i=1;i<=m;i++)ans[i] = my;
	for(i=1;i<=n;i++){
		for(k=0;k<v[i].size();k++){
			int j = v[i][k];
			int sz = s[i][k];
			int a=mod, b=mod, c=0;
			for(;sz;sz--, j++){
				a = min(a, up[i][j]);
				b = min(b, down[i][j]);
				c++;
				ans[c] = min(ans[c], a+b-1);
			}
		}
		
		for(k=(int)v[i].size()-1;k>=0;k--){
			int sz = s[i][k];
			int j = v[i][k]+sz-1;
			int a=mod, b=mod, c=0;
			for(;sz;sz--, j--){
				a = min(a, up[i][j]);
				b = min(b, down[i][j]);
				c++;
				ans[c] = min(ans[c], a+b-1);
			}
		}
		
	}
//	cout << mx << ' ' << my << '\n';
	for(i=2;i<=mx;i++)ans[i] = min(ans[i], ans[i-1]);
	int res = 0;
//	for(i=1;i<=mx;i++)cout << ans[i] << ' '; cout << '\n';
	for(i=1;i<=mx;i++)res = max(res, i*ans[i]);
	cout << res << '\n';
	return;
}

signed main(){
	FASTIO;
#define MULTITEST 0
#if MULTITEST
	int ___T;
	cin >> ___T;
	for(int T_CASE = 1; T_CASE <= ___T; T_CASE++)
		solve(T_CASE);
#else
	solve(1);
#endif
	return 0;
}
/*

6 6
000111
011111
011111
111000
111000
111000


*/

Compilation message

bomb.cpp: In function 'void solve(int)':
bomb.cpp:88:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   88 |   for(k=0;k<v[i].size();k++){
      |           ~^~~~~~~~~~~~

Subtask #1

100.0 / 100.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	1 ms	492 KB	Output is correct
2	Correct	1 ms	748 KB	Output is correct
3	Correct	25 ms	42988 KB	Output is correct
4	Correct	24 ms	42988 KB	Output is correct
5	Correct	1 ms	492 KB	Output is correct
6	Correct	1 ms	512 KB	Output is correct
7	Correct	1 ms	620 KB	Output is correct
8	Correct	1 ms	748 KB	Output is correct
9	Correct	1 ms	748 KB	Output is correct
10	Correct	1 ms	748 KB	Output is correct
11	Correct	1 ms	748 KB	Output is correct
12	Correct	1 ms	748 KB	Output is correct
13	Correct	1 ms	748 KB	Output is correct
14	Correct	1 ms	748 KB	Output is correct
15	Correct	1 ms	748 KB	Output is correct
16	Correct	1 ms	876 KB	Output is correct
17	Correct	1 ms	1644 KB	Output is correct
18	Correct	1 ms	1260 KB	Output is correct
19	Correct	2 ms	1644 KB	Output is correct
20	Correct	2 ms	1644 KB	Output is correct
21	Correct	1 ms	876 KB	Output is correct
22	Correct	1 ms	1260 KB	Output is correct
23	Correct	1 ms	1772 KB	Output is correct
24	Correct	1 ms	1644 KB	Output is correct
25	Correct	2 ms	2156 KB	Output is correct
26	Correct	2 ms	2284 KB	Output is correct
27	Correct	6 ms	6508 KB	Output is correct
28	Correct	4 ms	2668 KB	Output is correct
29	Correct	8 ms	8428 KB	Output is correct
30	Correct	9 ms	7276 KB	Output is correct
31	Correct	7 ms	5356 KB	Output is correct
32	Correct	8 ms	7020 KB	Output is correct
33	Correct	10 ms	8940 KB	Output is correct
34	Correct	4 ms	3052 KB	Output is correct
35	Correct	6 ms	3948 KB	Output is correct
36	Correct	12 ms	10476 KB	Output is correct
37	Correct	1 ms	876 KB	Output is correct
38	Correct	318 ms	86444 KB	Output is correct
39	Correct	1 ms	896 KB	Output is correct
40	Correct	39 ms	24428 KB	Output is correct
41	Correct	1 ms	876 KB	Output is correct
42	Correct	2 ms	2284 KB	Output is correct
43	Correct	268 ms	82540 KB	Output is correct
44	Correct	11 ms	9964 KB	Output is correct
45	Correct	259 ms	83948 KB	Output is correct
46	Correct	205 ms	87660 KB	Output is correct
47	Correct	260 ms	83948 KB	Output is correct
48	Correct	245 ms	86380 KB	Output is correct
49	Correct	318 ms	86508 KB	Output is correct
50	Correct	251 ms	86380 KB	Output is correct
51	Correct	251 ms	86380 KB	Output is correct
52	Correct	266 ms	86380 KB	Output is correct
53	Correct	252 ms	85740 KB	Output is correct
54	Correct	203 ms	73196 KB	Output is correct
55	Correct	202 ms	70636 KB	Output is correct
56	Correct	326 ms	87660 KB	Output is correct
57	Correct	194 ms	63852 KB	Output is correct
58	Correct	204 ms	71404 KB	Output is correct
59	Correct	204 ms	67052 KB	Output is correct
60	Correct	237 ms	78312 KB	Output is correct
61	Correct	313 ms	86508 KB	Output is correct
62	Correct	296 ms	86380 KB	Output is correct
63	Correct	311 ms	86508 KB	Output is correct
64	Correct	198 ms	69356 KB	Output is correct
65	Correct	256 ms	85484 KB	Output is correct
66	Correct	242 ms	82284 KB	Output is correct
67	Correct	261 ms	86508 KB	Output is correct
68	Correct	267 ms	86508 KB	Output is correct
69	Correct	197 ms	63084 KB	Output is correct
70	Correct	105 ms	34284 KB	Output is correct
71	Correct	164 ms	55148 KB	Output is correct
72	Correct	178 ms	61292 KB	Output is correct
73	Correct	187 ms	61548 KB	Output is correct
74	Correct	179 ms	64192 KB	Output is correct
75	Correct	185 ms	66308 KB	Output is correct
76	Correct	186 ms	68204 KB	Output is correct
77	Correct	193 ms	68588 KB	Output is correct
78	Correct	185 ms	68972 KB	Output is correct
79	Correct	143 ms	33516 KB	Output is correct
80	Correct	143 ms	35564 KB	Output is correct
81	Correct	155 ms	35436 KB	Output is correct
82	Correct	198 ms	72300 KB	Output is correct
83	Correct	195 ms	72684 KB	Output is correct
84	Correct	137 ms	25964 KB	Output is correct
85	Correct	191 ms	71788 KB	Output is correct
86	Correct	303 ms	85384 KB	Output is correct
87	Correct	194 ms	70764 KB	Output is correct
88	Correct	194 ms	70636 KB	Output is correct
89	Correct	237 ms	80364 KB	Output is correct
90	Correct	121 ms	54252 KB	Output is correct
91	Correct	209 ms	75628 KB	Output is correct
92	Correct	234 ms	77164 KB	Output is correct
93	Correct	297 ms	84460 KB	Output is correct
94	Correct	236 ms	79084 KB	Output is correct
95	Correct	199 ms	72684 KB	Output is correct
96	Correct	197 ms	72068 KB	Output is correct
97	Correct	300 ms	85228 KB	Output is correct
98	Correct	200 ms	71788 KB	Output is correct
99	Correct	231 ms	78700 KB	Output is correct
100	Correct	292 ms	84076 KB	Output is correct