Submission #169628

# Submission time Handle Problem Language Result Execution time Memory
169628 2019-12-21T16:58:14 Z davitmarg Bomb (IZhO17_bomb) C++17
60 / 100
1000 ms 98616 KB
/*DavitMarg*/
#include <iostream>
#include <algorithm>
#include <cmath>
#include <vector>
#include <string>
#include <cstring>
#include <map>
#include <unordered_map>
#include <set>
#include <queue>
#include <iomanip>
#include <bitset>
#include <stack>
#include <cassert>
#include <iterator>
#include <fstream>
#define mod 1000000007ll
#define LL long long
#define LD long double
#define MP make_pair
#define PB push_back
#define all(v) v.begin(), v.end()
using namespace std;

const int N = 2505;

int n, m, a[N][N], pr[N][N], lst[N][N], nxt[N][N];
char x;
int ans = 1;

void add(int sy, int sx, int y, int x)
{
    pr[sy][sx]++;
    pr[y][x]++;
    pr[sy][x]--;
    pr[y][sx]--;
}

int get(int sy, int sx, int y, int x)
{
    return a[y][x] - a[sy - 1][x] - a[y][sx - 1] + a[sy - 1][sx - 1];
}

bool check(int k, int q)
{
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= m; j++)
            pr[i][j] = 0;
    for (int i = 1; i + k - 1 <= n; i++)
        for (int j = 1; j + q - 1 <= m; j++)
            if (get(i, j, i + k - 1, j + q - 1) == k * q)
                add(i, j, i + k, j + q);
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= m; j++)
        {
            pr[i][j] += pr[i - 1][j] + pr[i][j - 1] - pr[i - 1][j - 1];
            if (get(i, j, i, j) != (bool)(pr[i][j]))
                return 0;
        }
    return 1;
}

void solve(int k)
{
    int l = max(ans / k, 1), r = m, mid;
    while (l <= r)
    {
        mid = (l + r) / 2;
        if (check(k, mid))
        {
            if (k * mid >= ans)
                ans = k * mid;
            l = mid + 1;
        }
        else
            r = mid - 1;
    }
}

int main()
{
    cin >> n >> m;

    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= m; j++)
        {
            scanf(" %c", &x);
            a[i][j] += (x - '0');
            a[i][j] += a[i - 1][j] + a[i][j - 1] - a[i - 1][j - 1];
        }

    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= m; j++)
            if (get(i, j, i, j))
                lst[i][j] = 1 + lst[i - 1][j];

    int len = n;
    for (int i = n; i >= 1; i--)
        for (int j = m; j >= 1; j--)
            if (get(i, j, i, j))
            {
                nxt[i][j] = 1 + nxt[i + 1][j];
                len = min(len, nxt[i][j] + lst[i][j] - 1);
            }
    if (n <= 450)
        for (int i = 1; i <= len; i++)
            solve(i);
    else
    {
        for (int i = 1; i <= len; i++)
            if (rand() % 40 == 0)
                solve(i);
        solve(len);
    }
    cout << ans << endl;
    return 0;
}

/*
 
6 6
000111
000111
001111
111100
111000
111000
 
*/

Compilation message

bomb.cpp: In function 'int main()':
bomb.cpp:88:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
             scanf(" %c", &x);
             ~~~~~^~~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Correct 2 ms 504 KB Output is correct
2 Correct 2 ms 632 KB Output is correct
3 Correct 37 ms 40440 KB Output is correct
4 Correct 37 ms 40444 KB Output is correct
5 Correct 3 ms 376 KB Output is correct
6 Correct 2 ms 376 KB Output is correct
7 Correct 2 ms 376 KB Output is correct
8 Correct 2 ms 632 KB Output is correct
9 Correct 2 ms 632 KB Output is correct
10 Correct 2 ms 632 KB Output is correct
11 Correct 2 ms 632 KB Output is correct
12 Correct 2 ms 632 KB Output is correct
13 Correct 2 ms 504 KB Output is correct
14 Correct 2 ms 632 KB Output is correct
15 Correct 2 ms 632 KB Output is correct
16 Correct 2 ms 632 KB Output is correct
17 Correct 4 ms 1528 KB Output is correct
18 Correct 3 ms 1272 KB Output is correct
19 Correct 6 ms 1656 KB Output is correct
20 Correct 6 ms 1660 KB Output is correct
21 Correct 3 ms 888 KB Output is correct
22 Correct 4 ms 1272 KB Output is correct
23 Correct 7 ms 1784 KB Output is correct
24 Correct 5 ms 1528 KB Output is correct
25 Correct 10 ms 2040 KB Output is correct
26 Correct 7 ms 2168 KB Output is correct
27 Correct 14 ms 6136 KB Output is correct
28 Correct 29 ms 3960 KB Output is correct
29 Correct 251 ms 8252 KB Output is correct
30 Correct 431 ms 8184 KB Output is correct
31 Correct 252 ms 6136 KB Output is correct
32 Correct 402 ms 7544 KB Output is correct
33 Correct 652 ms 9336 KB Output is correct
34 Correct 25 ms 4344 KB Output is correct
35 Correct 87 ms 6136 KB Output is correct
36 Correct 416 ms 10772 KB Output is correct
37 Correct 2 ms 632 KB Output is correct
38 Execution timed out 1071 ms 98340 KB Time limit exceeded
39 Correct 2 ms 632 KB Output is correct
40 Incorrect 251 ms 26488 KB Output isn't correct
41 Correct 3 ms 632 KB Output is correct
42 Correct 12 ms 2040 KB Output is correct
43 Execution timed out 1072 ms 94548 KB Time limit exceeded
44 Correct 910 ms 10180 KB Output is correct
45 Execution timed out 1074 ms 95796 KB Time limit exceeded
46 Correct 639 ms 98424 KB Output is correct
47 Execution timed out 1079 ms 95988 KB Time limit exceeded
48 Correct 696 ms 98544 KB Output is correct
49 Correct 704 ms 98424 KB Output is correct
50 Correct 734 ms 98436 KB Output is correct
51 Correct 807 ms 98448 KB Output is correct
52 Correct 718 ms 98604 KB Output is correct
53 Correct 762 ms 97740 KB Output is correct
54 Correct 716 ms 85316 KB Output is correct
55 Correct 779 ms 83448 KB Output is correct
56 Execution timed out 1075 ms 98552 KB Time limit exceeded
57 Correct 784 ms 78664 KB Output is correct
58 Correct 782 ms 83576 KB Output is correct
59 Correct 822 ms 80404 KB Output is correct
60 Correct 689 ms 90360 KB Output is correct
61 Correct 762 ms 98464 KB Output is correct
62 Execution timed out 1079 ms 98496 KB Time limit exceeded
63 Execution timed out 1087 ms 98552 KB Time limit exceeded
64 Execution timed out 1084 ms 81272 KB Time limit exceeded
65 Correct 756 ms 97528 KB Output is correct
66 Correct 692 ms 94200 KB Output is correct
67 Correct 807 ms 98468 KB Output is correct
68 Correct 751 ms 98616 KB Output is correct
69 Correct 741 ms 78072 KB Output is correct
70 Execution timed out 1055 ms 49584 KB Time limit exceeded
71 Execution timed out 1071 ms 71064 KB Time limit exceeded
72 Execution timed out 1070 ms 76476 KB Time limit exceeded
73 Execution timed out 1072 ms 77048 KB Time limit exceeded
74 Execution timed out 1072 ms 78588 KB Time limit exceeded
75 Execution timed out 1088 ms 80248 KB Time limit exceeded
76 Execution timed out 1085 ms 81580 KB Time limit exceeded
77 Execution timed out 1084 ms 82008 KB Time limit exceeded
78 Execution timed out 1080 ms 82180 KB Time limit exceeded
79 Execution timed out 1052 ms 54860 KB Time limit exceeded
80 Execution timed out 1067 ms 56084 KB Time limit exceeded
81 Execution timed out 1081 ms 56256 KB Time limit exceeded
82 Execution timed out 1078 ms 84656 KB Time limit exceeded
83 Execution timed out 1084 ms 84984 KB Time limit exceeded
84 Incorrect 563 ms 50184 KB Output isn't correct
85 Execution timed out 1080 ms 83704 KB Time limit exceeded
86 Incorrect 684 ms 97400 KB Output isn't correct
87 Execution timed out 1083 ms 82680 KB Time limit exceeded
88 Execution timed out 1088 ms 83836 KB Time limit exceeded
89 Execution timed out 1086 ms 92252 KB Time limit exceeded
90 Execution timed out 1074 ms 63864 KB Time limit exceeded
91 Execution timed out 1088 ms 87548 KB Time limit exceeded
92 Execution timed out 1082 ms 89152 KB Time limit exceeded
93 Incorrect 682 ms 96608 KB Output isn't correct
94 Execution timed out 1086 ms 91000 KB Time limit exceeded
95 Execution timed out 1087 ms 84856 KB Time limit exceeded
96 Execution timed out 1090 ms 84600 KB Time limit exceeded
97 Incorrect 673 ms 97144 KB Output isn't correct
98 Execution timed out 1083 ms 84348 KB Time limit exceeded
99 Execution timed out 1079 ms 90616 KB Time limit exceeded
100 Incorrect 668 ms 95996 KB Output isn't correct