| # |
Submission time |
Handle |
Problem |
Language |
Result |
Execution time |
Memory |
| 404583 |
2021-05-14T16:55:05 Z |
rama_pang |
Bomb (IZhO17_bomb) |
C++17 |
|
442 ms |
74348 KB |
#include <bits/stdc++.h>
using namespace std;
int N, M;
int A[2505][2505];
int up[2505][2505];
int dn[2505][2505];
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
cin >> N >> M;
for (int i = 1; i <= N; i++) {
for (int j = 1; j <= M; j++) {
char c;
cin >> c;
A[i][j] = c - '0';
}
}
// Solution:
//
// The upper bound on height and width is the minimum length
// vertical and horizontal strip. Now, for a fixed width Y,
// we want to determine the maximum height X. Note that,
// if we have width Y, then for every maximal horizontal
// strip, height is bounded by the minimum (top - bottom)
// of the prefix and suffix of size Y.
//
// We only need to consider the prefix and suffix. Why?
// For, after a prefix of size Y, let's move it to the right.
// If the (top - bottom) decreased, that means that there is
// a vertical strip which is shifted downwards, which means
// it will occcupy a maximal horizontal strip -> we will compute
// it later.
//
// Time complexity: O(N M).
for (int j = 1; j <= M; j++) {
for (int i = 1; i <= N; i++) {
if (A[i][j]) {
up[i][j] = 1 + up[i - 1][j];
}
}
for (int i = N; i >= 1; i--) {
if (A[i][j]) {
dn[i][j] = 1 + dn[i + 1][j];
}
}
}
vector<int> ans(M + 2, 1e9);
for (int rep = 0; rep < 2; rep++) { // for prefix, then suffix
for (int i = 1; i <= N; i++) {
for (int j = 1; j <= M; j++) if (A[i][j]) {
int jj = j;
while (jj + 1 <= M && A[i][jj + 1]) jj += 1;
int len = jj - j + 1;
int minUp = 1e9;
int minDn = 1e9;
for (int k = 1; k <= len; k++) {
minUp = min(minUp, up[i][j + k - 1]);
minDn = min(minDn, dn[i][j + k - 1]);
ans[k] = min(ans[k], minUp + minDn - 1);
}
ans[0] = min(ans[0], up[i][j] + dn[i][j] - 1);
ans[len + 1] = 0;
j = jj;
}
}
for (int i = 1; i <= N; i++) {
for (int j = 1; j + j <= M; j++) {
swap(A[i][j], A[i][M - j + 1]);
swap(up[i][j], up[i][M - j + 1]);
swap(dn[i][j], dn[i][M - j + 1]);
}
}
}
int answer = 0;
for (int i = 1; i <= M; i++) {
ans[i] = min(ans[i], ans[i - 1]);
answer = max(answer, i * ans[i]);
}
cout << answer << '\n';
return 0;
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
332 KB |
Output is correct |
| 2 |
Correct |
2 ms |
456 KB |
Output is correct |
| 3 |
Correct |
15 ms |
30396 KB |
Output is correct |
| 4 |
Correct |
16 ms |
30396 KB |
Output is correct |
| 5 |
Correct |
1 ms |
332 KB |
Output is correct |
| 6 |
Correct |
1 ms |
316 KB |
Output is correct |
| 7 |
Incorrect |
1 ms |
332 KB |
Output isn't correct |
| 8 |
Correct |
1 ms |
460 KB |
Output is correct |
| 9 |
Correct |
1 ms |
460 KB |
Output is correct |
| 10 |
Correct |
1 ms |
460 KB |
Output is correct |
| 11 |
Correct |
1 ms |
460 KB |
Output is correct |
| 12 |
Correct |
1 ms |
460 KB |
Output is correct |
| 13 |
Correct |
1 ms |
448 KB |
Output is correct |
| 14 |
Correct |
1 ms |
460 KB |
Output is correct |
| 15 |
Correct |
1 ms |
452 KB |
Output is correct |
| 16 |
Correct |
1 ms |
460 KB |
Output is correct |
| 17 |
Correct |
1 ms |
1096 KB |
Output is correct |
| 18 |
Correct |
1 ms |
1228 KB |
Output is correct |
| 19 |
Correct |
2 ms |
1484 KB |
Output is correct |
| 20 |
Correct |
2 ms |
1484 KB |
Output is correct |
| 21 |
Correct |
1 ms |
972 KB |
Output is correct |
| 22 |
Correct |
2 ms |
1228 KB |
Output is correct |
| 23 |
Correct |
2 ms |
1612 KB |
Output is correct |
| 24 |
Correct |
2 ms |
1348 KB |
Output is correct |
| 25 |
Correct |
2 ms |
1612 KB |
Output is correct |
| 26 |
Incorrect |
2 ms |
1608 KB |
Output isn't correct |
| 27 |
Incorrect |
6 ms |
4888 KB |
Output isn't correct |
| 28 |
Correct |
6 ms |
5196 KB |
Output is correct |
| 29 |
Correct |
8 ms |
6604 KB |
Output is correct |
| 30 |
Correct |
10 ms |
7812 KB |
Output is correct |
| 31 |
Correct |
8 ms |
6216 KB |
Output is correct |
| 32 |
Correct |
8 ms |
7116 KB |
Output is correct |
| 33 |
Correct |
11 ms |
8256 KB |
Output is correct |
| 34 |
Correct |
6 ms |
5580 KB |
Output is correct |
| 35 |
Correct |
11 ms |
8256 KB |
Output is correct |
| 36 |
Incorrect |
14 ms |
8264 KB |
Output isn't correct |
| 37 |
Correct |
1 ms |
460 KB |
Output is correct |
| 38 |
Correct |
440 ms |
74052 KB |
Output is correct |
| 39 |
Correct |
1 ms |
460 KB |
Output is correct |
| 40 |
Correct |
65 ms |
20036 KB |
Output is correct |
| 41 |
Correct |
1 ms |
460 KB |
Output is correct |
| 42 |
Correct |
2 ms |
1612 KB |
Output is correct |
| 43 |
Correct |
383 ms |
74036 KB |
Output is correct |
| 44 |
Correct |
11 ms |
8232 KB |
Output is correct |
| 45 |
Correct |
372 ms |
73972 KB |
Output is correct |
| 46 |
Correct |
369 ms |
74184 KB |
Output is correct |
| 47 |
Correct |
374 ms |
74084 KB |
Output is correct |
| 48 |
Correct |
360 ms |
74116 KB |
Output is correct |
| 49 |
Incorrect |
431 ms |
73952 KB |
Output isn't correct |
| 50 |
Correct |
387 ms |
74016 KB |
Output is correct |
| 51 |
Correct |
363 ms |
73860 KB |
Output is correct |
| 52 |
Correct |
367 ms |
73904 KB |
Output is correct |
| 53 |
Correct |
361 ms |
73948 KB |
Output is correct |
| 54 |
Correct |
332 ms |
73904 KB |
Output is correct |
| 55 |
Correct |
310 ms |
73988 KB |
Output is correct |
| 56 |
Correct |
435 ms |
74104 KB |
Output is correct |
| 57 |
Correct |
310 ms |
74052 KB |
Output is correct |
| 58 |
Correct |
313 ms |
74044 KB |
Output is correct |
| 59 |
Correct |
317 ms |
74072 KB |
Output is correct |
| 60 |
Incorrect |
351 ms |
74092 KB |
Output isn't correct |
| 61 |
Incorrect |
433 ms |
74348 KB |
Output isn't correct |
| 62 |
Incorrect |
442 ms |
73924 KB |
Output isn't correct |
| 63 |
Incorrect |
431 ms |
74024 KB |
Output isn't correct |
| 64 |
Incorrect |
308 ms |
73976 KB |
Output isn't correct |
| 65 |
Correct |
367 ms |
73920 KB |
Output is correct |
| 66 |
Correct |
353 ms |
73936 KB |
Output is correct |
| 67 |
Correct |
382 ms |
73884 KB |
Output is correct |
| 68 |
Correct |
377 ms |
74124 KB |
Output is correct |
| 69 |
Correct |
308 ms |
74092 KB |
Output is correct |
| 70 |
Correct |
183 ms |
59252 KB |
Output is correct |
| 71 |
Correct |
286 ms |
73996 KB |
Output is correct |
| 72 |
Correct |
303 ms |
74076 KB |
Output is correct |
| 73 |
Correct |
339 ms |
73984 KB |
Output is correct |
| 74 |
Correct |
366 ms |
73988 KB |
Output is correct |
| 75 |
Correct |
306 ms |
74064 KB |
Output is correct |
| 76 |
Correct |
329 ms |
74140 KB |
Output is correct |
| 77 |
Correct |
314 ms |
73928 KB |
Output is correct |
| 78 |
Correct |
312 ms |
74048 KB |
Output is correct |
| 79 |
Correct |
261 ms |
73924 KB |
Output is correct |
| 80 |
Correct |
261 ms |
73928 KB |
Output is correct |
| 81 |
Correct |
272 ms |
74112 KB |
Output is correct |
| 82 |
Correct |
345 ms |
74104 KB |
Output is correct |
| 83 |
Correct |
319 ms |
74236 KB |
Output is correct |
| 84 |
Correct |
260 ms |
74016 KB |
Output is correct |
| 85 |
Correct |
311 ms |
74208 KB |
Output is correct |
| 86 |
Correct |
442 ms |
74004 KB |
Output is correct |
| 87 |
Correct |
310 ms |
74168 KB |
Output is correct |
| 88 |
Correct |
317 ms |
74012 KB |
Output is correct |
| 89 |
Correct |
347 ms |
73924 KB |
Output is correct |
| 90 |
Correct |
199 ms |
59204 KB |
Output is correct |
| 91 |
Correct |
355 ms |
73980 KB |
Output is correct |
| 92 |
Correct |
355 ms |
73996 KB |
Output is correct |
| 93 |
Correct |
413 ms |
73920 KB |
Output is correct |
| 94 |
Correct |
361 ms |
73968 KB |
Output is correct |
| 95 |
Correct |
312 ms |
73884 KB |
Output is correct |
| 96 |
Correct |
326 ms |
74008 KB |
Output is correct |
| 97 |
Correct |
421 ms |
74168 KB |
Output is correct |
| 98 |
Correct |
313 ms |
74128 KB |
Output is correct |
| 99 |
Correct |
372 ms |
74148 KB |
Output is correct |
| 100 |
Correct |
415 ms |
74016 KB |
Output is correct |
