oj.uz

Submission #423303

# Submission time Handle Problem Language Result Execution time Memory
423303 2021-06-10T23:14:37 Z antimirage Bomb (IZhO17_bomb) C++14
100 / 100
 734 ms 74844 KB 
/*
 *  let's for fixed width X find the maximum valid height Y, denote it by ans[X]. 
 *  upper bound of Y for every X is ans[1].
 *   
*/
#include <iostream>
#include <vector>
#include <algorithm>
#include <assert.h>

using namespace std;

int main() {
    int n, m, res = 0;
    cin >> n >> m;
    vector <vector <int>> a(n + 5, vector<int>(m + 5, 0));
    for (int i = 1; i <= n; i++) {
        scanf("\n");
        for (int j = 1; j <= m; j++) {
            char ch;
            scanf("%c", &ch);
            a[i][j] = ch - 48;
        }
    }
    vector <vector <int>> up(n + 5, vector<int>(m + 5, 0));
    vector <vector <int>> dn(n + 5, vector<int>(m + 5, 0));
    
    for (int j = 1; j <= m; j++) {
        for (int i = 1; i <= n; i++) {
            up[i][j] = a[i][j] ? up[i - 1][j] + 1 : 0;
        }
        for (int i = n; i >= 1; i--) {
            dn[i][j] = a[i][j] ? dn[i + 1][j] + 1 : 0;
        }
    }
    vector <int> ans(m + 5, n);
    for (int t = 0; t < 2; t++) {
        for (int i = 1; i <= n; i++) {
            for (int j = 1; j <= m; j++) {
                if (a[i][j])
                    ans[1] = min(ans[1], up[i][j] + dn[i][j] - 1);
            }
            for (int j = 1; j <= m; j++) {
                if (a[i][j] && !a[i][j - 1]) {
                    int min_d = n, min_u = n, k;
                    
                    for (k = j; a[i][k]; k++) {
                        min_d = min(min_d, dn[i][k]);
                        min_u = min(min_u, up[i][k]);
                        ans[k - j + 1] = min(ans[k - j + 1], min_d + min_u - 1);
                    } 
                    ans[k - j + 1] = 0;
                }
            }
        }
        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]);
            }
        }
    }
    for (int i = 1; i <= m; i++) {
        ans[i] = min(ans[i], ans[i - 1]);
        res = max(res, i * ans[i]);
        //cout << i << " --> " << ans[i] << endl;
    }
    cout << res << endl;
}

Compilation message

bomb.cpp: In function 'int main()':
bomb.cpp:18:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   18 |         scanf("\n");
      |         ~~~~~^~~~~~
bomb.cpp:21:18: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   21 |             scanf("%c", &ch);
      |             ~~~~~^~~~~~~~~~~

Subtask #1
100.0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 1 ms 588 KB Output is correct
4 Correct 1 ms 600 KB Output is correct
5 Correct 1 ms 408 KB Output is correct
6 Correct 1 ms 332 KB Output is correct
7 Correct 1 ms 204 KB Output is correct
8 Correct 1 ms 204 KB Output is correct
9 Correct 1 ms 204 KB Output is correct
10 Correct 1 ms 204 KB Output is correct
11 Correct 1 ms 204 KB Output is correct
12 Correct 1 ms 204 KB Output is correct
13 Correct 1 ms 204 KB Output is correct
14 Correct 1 ms 292 KB Output is correct
15 Correct 1 ms 204 KB Output is correct
16 Correct 1 ms 204 KB Output is correct
17 Correct 1 ms 332 KB Output is correct
18 Correct 1 ms 332 KB Output is correct
19 Correct 1 ms 332 KB Output is correct
20 Correct 1 ms 296 KB Output is correct
21 Correct 1 ms 332 KB Output is correct
22 Correct 1 ms 332 KB Output is correct
23 Correct 1 ms 332 KB Output is correct
24 Correct 1 ms 332 KB Output is correct
25 Correct 1 ms 400 KB Output is correct
26 Correct 1 ms 332 KB Output is correct
27 Correct 8 ms 1356 KB Output is correct
28 Correct 10 ms 1780 KB Output is correct
29 Correct 12 ms 1952 KB Output is correct
30 Correct 17 ms 2784 KB Output is correct
31 Correct 14 ms 2184 KB Output is correct
32 Correct 14 ms 2340 KB Output is correct
33 Correct 18 ms 2892 KB Output is correct
34 Correct 7 ms 1356 KB Output is correct
35 Correct 17 ms 2892 KB Output is correct
36 Correct 20 ms 2912 KB Output is correct
37 Correct 1 ms 204 KB Output is correct
38 Correct 727 ms 74720 KB Output is correct
39 Correct 1 ms 204 KB Output is correct
40 Correct 83 ms 9680 KB Output is correct
41 Correct 1 ms 292 KB Output is correct
42 Correct 1 ms 332 KB Output is correct
43 Correct 696 ms 74392 KB Output is correct
44 Correct 19 ms 2892 KB Output is correct
45 Correct 692 ms 74580 KB Output is correct
46 Correct 706 ms 74480 KB Output is correct
47 Correct 689 ms 74476 KB Output is correct
48 Correct 686 ms 74456 KB Output is correct
49 Correct 712 ms 74484 KB Output is correct
50 Correct 733 ms 74460 KB Output is correct
51 Correct 698 ms 74592 KB Output is correct
52 Correct 704 ms 74480 KB Output is correct
53 Correct 696 ms 74592 KB Output is correct
54 Correct 679 ms 74480 KB Output is correct
55 Correct 676 ms 74460 KB Output is correct
56 Correct 728 ms 74460 KB Output is correct
57 Correct 679 ms 74704 KB Output is correct
58 Correct 679 ms 74564 KB Output is correct
59 Correct 672 ms 74432 KB Output is correct
60 Correct 685 ms 74516 KB Output is correct
61 Correct 715 ms 74460 KB Output is correct
62 Correct 734 ms 74456 KB Output is correct
63 Correct 723 ms 74480 KB Output is correct
64 Correct 676 ms 74692 KB Output is correct
65 Correct 685 ms 74476 KB Output is correct
66 Correct 689 ms 74436 KB Output is correct
67 Correct 701 ms 74816 KB Output is correct
68 Correct 708 ms 74584 KB Output is correct
69 Correct 674 ms 74484 KB Output is correct
70 Correct 421 ms 47944 KB Output is correct
71 Correct 665 ms 74516 KB Output is correct
72 Correct 684 ms 74480 KB Output is correct
73 Correct 672 ms 74480 KB Output is correct
74 Correct 680 ms 74844 KB Output is correct
75 Correct 683 ms 74476 KB Output is correct
76 Correct 672 ms 74480 KB Output is correct
77 Correct 693 ms 74436 KB Output is correct
78 Correct 675 ms 74692 KB Output is correct
79 Correct 663 ms 74584 KB Output is correct
80 Correct 659 ms 74580 KB Output is correct
81 Correct 659 ms 74480 KB Output is correct
82 Correct 687 ms 74776 KB Output is correct
83 Correct 685 ms 74640 KB Output is correct
84 Correct 668 ms 74476 KB Output is correct
85 Correct 688 ms 74472 KB Output is correct
86 Correct 715 ms 74468 KB Output is correct
87 Correct 674 ms 74476 KB Output is correct
88 Correct 688 ms 74576 KB Output is correct
89 Correct 699 ms 74592 KB Output is correct
90 Correct 446 ms 47944 KB Output is correct
91 Correct 687 ms 74580 KB Output is correct
92 Correct 689 ms 74720 KB Output is correct
93 Correct 707 ms 74588 KB Output is correct
94 Correct 694 ms 74472 KB Output is correct
95 Correct 685 ms 74564 KB Output is correct
96 Correct 682 ms 74436 KB Output is correct
97 Correct 725 ms 74476 KB Output is correct
98 Correct 683 ms 74564 KB Output is correct
99 Correct 699 ms 74584 KB Output is correct
100 Correct 706 ms 74504 KB Output is correct