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Submission #100306

# Submission time Handle Problem Language Result Execution time Memory
100306 2019-03-10T10:49:18 Z naoai Bomb (IZhO17_bomb) C++14
100 / 100
 603 ms 62716 KB 
#include <bits/stdc++.h>

using namespace std;

#define fin cin
#define fout cout
//ifstream fin("x.in"); ofstream fout("x.out");

const int nmax = 2500 + 5;
const int inf = 1 << 30;

int n, m;
int v[nmax + 1][nmax + 1];
int u[nmax + 1][nmax + 1];

int w[nmax + 1];
int st[nmax + 1][nmax + 1], dr[nmax + 1][nmax + 1];
string s[nmax + 1];

void check (int h, int w) {
    for (int i = 1; i <= n; ++ i) {
        for (int j = 1; j <= m; ++ j) {
            v[i][j] = v[i - 1][j] + v[i][j - 1] - v[i - 1][j - 1] + (s[i][j - 1] - '0');
        }
    }

    bool ok = 1;
    for (int i = 1; i <= n - h + 1; ++ i) {
        for (int j = 1; j <= m - w + 1; ++ j) {
            int sum = v[i + h - 1][j + w - 1] - v[i - 1][j + w - 1] - v[i + h - 1][j - 1] + v[i - 1][j - 1];
            if (sum == h * w) {
                ++ u[i][j];
                ++ u[i + h][j + w];
                -- u[i + h][j];
                -- u[i][j + w];
            }
        }
    }

    for (int i = 1; i <= n; ++ i) {
        for (int j = 1; j <= m; ++ j) {
            u[i][j] += u[i - 1][j] + u[i][j - 1] - u[i - 1][j - 1];
            if ((u[i][j] == 0) != ((s[i][j - 1] - '0') == 0)) {
                assert(0);
            }
        }
    }
}

int main() {
    fin.sync_with_stdio(false); fin.tie(); fout.tie();
    fin >> n >> m;

    for (int i = 1; i <= n; ++ i)
        fin >> s[i];

    for (int i = 1; i <= n; ++ i) {
        s[i] = '0' + s[i] + '0';
    }

    s[0].resize(m + 2, '0');
    s[n + 1].resize(m + 2, '0');

    for (int i = 1; i <= n; ++ i) {
        st[i][0] = 1;
        for (int j = 1; j <= m; ++ j) {
            if (s[i][j] == '1')
                st[i][j] = st[i][j - 1];
            else
                st[i][j] = j + 1;
        }

        dr[i][m + 1] = m;
        for (int j = m; j > 0; -- j) {
            if (s[i][j] == '1')
                dr[i][j] = dr[i][j + 1];
            else
                dr[i][j] = j - 1;
        }
    }

    for (int i = 1; i <= n; ++ i)
        w[i] = inf;

    for (int i = 1; i <= n; ++ i) {
        for (int j = 1; j <= m; ++ j) {
            if (s[i - 1][j] == '0' && s[i][j] == '1') {
                int k = i;
                int mn = st[i][j], mx = dr[i][j];

                while (k <= m && s[k][j] == '1') {
                    mn = max(mn, st[k][j]);
                    mx = min(mx, dr[k][j]);
                    w[k - i + 1] = min(w[k - i + 1], mx - mn + 1);
                    ++ k;
                }
            }
        }

        for (int j = 1; j <= m; ++ j) {
            if (s[i + 1][j] == '0' && s[i][j] == '1') {
                int k = i;
                int mn = st[i][j], mx = dr[i][j];

                while (k > 0 && s[k][j] == '1') {
                    mn = max(mn, st[k][j]);
                    mx = min(mx, dr[k][j]);
                    w[i - k + 1] = min(w[i - k + 1], mx - mn + 1);
                    -- k;
                }
            }
        }
    }

    int h = inf;
    for (int j = 1; j <= m; ++ j) {
        int cnt = 0;
        for (int i = 1; i <= n; ++ i) {
            if (s[i][j] == '1')
                ++ cnt;
            else
                cnt = 0;

            if (s[i][j] == '1' && s[i + 1][j] == '0')
                h = min(h, cnt);
        }
    }

    int _w = inf;
    for (int i = 1; i <= n; ++ i) {
        int cnt = 0;
        for (int j = 1; j <= m; ++ j) {
            if (s[i][j] == '1')
                ++ cnt;
            else
                cnt = 0;

            if (s[i][j] == '1' && s[i][j + 1] == '0')
                _w = min(_w, cnt);
        }
    }

    int amax = 0;
    for (int i = 1; i <= h; ++ i) {
        if (w[i] != inf)
            amax = max(amax, i * min(w[i], _w));
    }

    cout << amax << "\n";

    return 0;
}

Compilation message

bomb.cpp: In function 'void check(int, int)':
bomb.cpp:27:10: warning: unused variable 'ok' [-Wunused-variable]
     bool ok = 1;
          ^~

Subtask #1
100.0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 384 KB Output is correct
2 Correct 2 ms 512 KB Output is correct
3 Correct 18 ms 20608 KB Output is correct
4 Correct 17 ms 20580 KB Output is correct
5 Correct 2 ms 512 KB Output is correct
6 Correct 3 ms 512 KB Output is correct
7 Correct 2 ms 512 KB Output is correct
8 Correct 2 ms 512 KB Output is correct
9 Correct 3 ms 640 KB Output is correct
10 Correct 3 ms 512 KB Output is correct
11 Correct 3 ms 640 KB Output is correct
12 Correct 2 ms 384 KB Output is correct
13 Correct 2 ms 512 KB Output is correct
14 Correct 2 ms 512 KB Output is correct
15 Correct 2 ms 640 KB Output is correct
16 Correct 2 ms 512 KB Output is correct
17 Correct 3 ms 1024 KB Output is correct
18 Correct 3 ms 1024 KB Output is correct
19 Correct 3 ms 1280 KB Output is correct
20 Correct 3 ms 1280 KB Output is correct
21 Correct 2 ms 896 KB Output is correct
22 Correct 3 ms 1152 KB Output is correct
23 Correct 3 ms 1280 KB Output is correct
24 Correct 3 ms 1152 KB Output is correct
25 Correct 3 ms 1408 KB Output is correct
26 Correct 17 ms 1280 KB Output is correct
27 Correct 24 ms 3676 KB Output is correct
28 Correct 8 ms 3968 KB Output is correct
29 Correct 11 ms 4992 KB Output is correct
30 Correct 8 ms 5888 KB Output is correct
31 Correct 7 ms 4736 KB Output is correct
32 Correct 7 ms 5376 KB Output is correct
33 Correct 9 ms 6272 KB Output is correct
34 Correct 6 ms 4096 KB Output is correct
35 Correct 9 ms 6272 KB Output is correct
36 Correct 12 ms 6272 KB Output is correct
37 Correct 2 ms 640 KB Output is correct
38 Correct 551 ms 62584 KB Output is correct
39 Correct 2 ms 640 KB Output is correct
40 Correct 39 ms 15744 KB Output is correct
41 Correct 2 ms 640 KB Output is correct
42 Correct 3 ms 1408 KB Output is correct
43 Correct 397 ms 62584 KB Output is correct
44 Correct 10 ms 6272 KB Output is correct
45 Correct 390 ms 62716 KB Output is correct
46 Correct 212 ms 62584 KB Output is correct
47 Correct 402 ms 62712 KB Output is correct
48 Correct 378 ms 62660 KB Output is correct
49 Correct 588 ms 62456 KB Output is correct
50 Correct 359 ms 62584 KB Output is correct
51 Correct 364 ms 62604 KB Output is correct
52 Correct 344 ms 62456 KB Output is correct
53 Correct 371 ms 62584 KB Output is correct
54 Correct 246 ms 62584 KB Output is correct
55 Correct 255 ms 62584 KB Output is correct
56 Correct 544 ms 62712 KB Output is correct
57 Correct 251 ms 62584 KB Output is correct
58 Correct 244 ms 62584 KB Output is correct
59 Correct 229 ms 62584 KB Output is correct
60 Correct 355 ms 62584 KB Output is correct
61 Correct 565 ms 62712 KB Output is correct
62 Correct 603 ms 62584 KB Output is correct
63 Correct 572 ms 62556 KB Output is correct
64 Correct 220 ms 62456 KB Output is correct
65 Correct 338 ms 62584 KB Output is correct
66 Correct 371 ms 62456 KB Output is correct
67 Correct 422 ms 62456 KB Output is correct
68 Correct 402 ms 62456 KB Output is correct
69 Correct 231 ms 62456 KB Output is correct
70 Correct 90 ms 48120 KB Output is correct
71 Correct 190 ms 62360 KB Output is correct
72 Correct 208 ms 62328 KB Output is correct
73 Correct 208 ms 62336 KB Output is correct
74 Correct 214 ms 62328 KB Output is correct
75 Correct 216 ms 62328 KB Output is correct
76 Correct 216 ms 62328 KB Output is correct
77 Correct 239 ms 62328 KB Output is correct
78 Correct 224 ms 62328 KB Output is correct
79 Correct 125 ms 62328 KB Output is correct
80 Correct 133 ms 62456 KB Output is correct
81 Correct 133 ms 62448 KB Output is correct
82 Correct 244 ms 62328 KB Output is correct
83 Correct 258 ms 62196 KB Output is correct
84 Correct 128 ms 62072 KB Output is correct
85 Correct 231 ms 62188 KB Output is correct
86 Correct 546 ms 62200 KB Output is correct
87 Correct 227 ms 62200 KB Output is correct
88 Correct 248 ms 62200 KB Output is correct
89 Correct 347 ms 62200 KB Output is correct
90 Correct 127 ms 48008 KB Output is correct
91 Correct 297 ms 62172 KB Output is correct
92 Correct 329 ms 62072 KB Output is correct
93 Correct 528 ms 62072 KB Output is correct
94 Correct 359 ms 62072 KB Output is correct
95 Correct 248 ms 61944 KB Output is correct
96 Correct 283 ms 62072 KB Output is correct
97 Correct 544 ms 62072 KB Output is correct
98 Correct 249 ms 62072 KB Output is correct
99 Correct 347 ms 62072 KB Output is correct
100 Correct 514 ms 62072 KB Output is correct