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Submission #1030388

# Submission time Handle Problem Language Result Execution time Memory
1030388 2024-07-22T04:23:59 Z caterpillow Bomb (IZhO17_bomb) C++17
42 / 100
 1000 ms 56984 KB 
#include <bits/stdc++.h>

using namespace std;

#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")

using ll = long long;
#define vt vector
#define f first
#define s second
#define all(x) (x).begin(), (x).end()
#define FOR(i, a, b)  for (int i = (a); i < (b); i++)
#define F0R(i, b) FOR(i, 0, b)
#define ROF(i, a, b) for (int i = (b) - 1; i >= (a); i--)
#define pb push_back
#define endl '\n'

#ifndef LOCAL
#define cerr if (0) std::cerr
#endif

/*

N^3: find max width for each given height

*/

int rs, cs;
vt<vt<bool>> grid;
vt<vt<int>> sfx;

int sum(int r1, int c1, int r2, int c2) {
    r2 = min(r2, rs - 1);
    c2 = min(c2, cs - 1);
    return sfx[r1][c1] - sfx[r1][c2 + 1] - sfx[r2 + 1][c1] + sfx[r2 + 1][c2 + 1];
}

bool check(int w, int h) {
    vt<vt<int>> pfx(rs, vt<int>(cs));
    auto is_covered = [&] (int r, int c) {
        return (pfx[r][c] - (r - h >= 0 ? pfx[r - h][c] : 0) - (c - w >= 0 ? pfx[r][c - w] : 0) + (r - h >= 0 && c - w >= 0 ? pfx[r - h][c - w] : 0)) > 0;
    };
    auto add = [&] (int r, int c) {
        pfx[r][c] += (r ? pfx[r - 1][c] : 0) + (c ? pfx[r][c - 1] : 0) - (r && c ? pfx[r - 1][c - 1] : 0);
    };

    F0R (r, rs - 1) {
        F0R (c, cs - 1) {
            if (sum(r, c, r + h - 1, c + w - 1) == w * h) {
                pfx[r][c]++;
            }
            add(r, c);
            if (grid[r][c] == 1) {
                if (!is_covered(r, c)) return false;
            }
        }
    }
    return true;
}

int solve(int mnh, int mxh, int mnw, int mxw) {
    if (mxh < mnh || mxw < mnw) return 0;
    int h = (mnh + mxh) / 2;
    int lo = mnw - 1, hi = mxw + 1;
    while (hi - lo > 1) {
        int w = (lo + hi) / 2;
        if (check(w, h)) lo = w;
        else hi = w;
    }
    return max({h * lo, solve(mnh, h - 1, lo, mxw), solve(h + 1, mxh, mnw, lo)});
}

main() {
    cin.tie(0)->sync_with_stdio();

    cin >> rs >> cs;
    rs += 2, cs += 2;
    grid.resize(rs, vt<bool>(cs));
    sfx.resize(rs + 1, vt<int>(cs + 1));
    FOR (r, 1, rs - 1) {
        FOR (c, 1, cs - 1) {
            char ch; cin >> ch;
            grid[r][c] = sfx[r][c] = ch - '0';
        }
    }
    ROF (r, 0, rs) ROF (c, 0, cs) sfx[r][c] += sfx[r][c + 1];
    ROF (r, 0, rs) ROF (c, 0, cs) sfx[r][c] += sfx[r + 1][c];

    int mxw = cs, mxh = rs;
    F0R (r, rs) {
        int streak = 0;
        F0R (c, cs) {
            if (grid[r][c]) streak++;
            else if (streak) mxw = min(mxw, streak), streak = 0;
        }
    }
    F0R (c, cs) {
        int streak = 0;
        F0R (r, rs) {
            if (grid[r][c]) streak++;
            else if (streak) mxh = min(mxh, streak), streak = 0;
        }
    }

    cerr << mxw << " " << mxh << endl;

    cout << solve(1, mxh, 1, mxw) << endl;
}

Compilation message

bomb.cpp:74:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   74 | main() {
      | ^~~~
bomb.cpp: In function 'int main()':
bomb.cpp:84:36: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
   84 |             grid[r][c] = sfx[r][c] = ch - '0';

Subtask #1
42.0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 4 ms 860 KB Output is correct
4 Correct 5 ms 884 KB Output is correct
5 Correct 1 ms 348 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 1 ms 344 KB Output is correct
8 Correct 0 ms 348 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 0 ms 352 KB Output is correct
11 Correct 1 ms 348 KB Output is correct
12 Correct 0 ms 348 KB Output is correct
13 Correct 0 ms 348 KB Output is correct
14 Correct 0 ms 348 KB Output is correct
15 Correct 0 ms 348 KB Output is correct
16 Correct 0 ms 348 KB Output is correct
17 Correct 1 ms 348 KB Output is correct
18 Correct 1 ms 348 KB Output is correct
19 Correct 1 ms 352 KB Output is correct
20 Correct 1 ms 444 KB Output is correct
21 Correct 0 ms 352 KB Output is correct
22 Correct 1 ms 440 KB Output is correct
23 Correct 2 ms 356 KB Output is correct
24 Correct 1 ms 344 KB Output is correct
25 Correct 3 ms 348 KB Output is correct
26 Correct 2 ms 348 KB Output is correct
27 Correct 3 ms 1180 KB Output is correct
28 Correct 8 ms 1436 KB Output is correct
29 Correct 107 ms 1728 KB Output is correct
30 Correct 126 ms 2292 KB Output is correct
31 Correct 68 ms 2164 KB Output is correct
32 Correct 91 ms 1892 KB Output is correct
33 Correct 163 ms 2320 KB Output is correct
34 Correct 7 ms 1220 KB Output is correct
35 Correct 37 ms 2316 KB Output is correct
36 Correct 78 ms 2416 KB Output is correct
37 Correct 0 ms 348 KB Output is correct
38 Execution timed out 1100 ms 56696 KB Time limit exceeded
39 Correct 1 ms 344 KB Output is correct
40 Execution timed out 1092 ms 7484 KB Time limit exceeded
41 Correct 0 ms 344 KB Output is correct
42 Correct 5 ms 348 KB Output is correct
43 Execution timed out 1094 ms 56604 KB Time limit exceeded
44 Correct 491 ms 2552 KB Output is correct
45 Execution timed out 1016 ms 56704 KB Time limit exceeded
46 Execution timed out 1072 ms 56692 KB Time limit exceeded
47 Execution timed out 1060 ms 56788 KB Time limit exceeded
48 Execution timed out 1044 ms 56728 KB Time limit exceeded
49 Correct 566 ms 56696 KB Output is correct
50 Execution timed out 1060 ms 56860 KB Time limit exceeded
51 Execution timed out 1067 ms 56744 KB Time limit exceeded
52 Execution timed out 1038 ms 56800 KB Time limit exceeded
53 Execution timed out 1024 ms 56744 KB Time limit exceeded
54 Execution timed out 1014 ms 56752 KB Time limit exceeded
55 Execution timed out 1071 ms 56792 KB Time limit exceeded
56 Execution timed out 1028 ms 56728 KB Time limit exceeded
57 Execution timed out 1063 ms 56828 KB Time limit exceeded
58 Execution timed out 1042 ms 56696 KB Time limit exceeded
59 Execution timed out 1074 ms 56656 KB Time limit exceeded
60 Execution timed out 1065 ms 56772 KB Time limit exceeded
61 Execution timed out 1065 ms 56696 KB Time limit exceeded
62 Execution timed out 1066 ms 56816 KB Time limit exceeded
63 Execution timed out 1018 ms 56952 KB Time limit exceeded
64 Execution timed out 1076 ms 56700 KB Time limit exceeded
65 Execution timed out 1069 ms 56708 KB Time limit exceeded
66 Execution timed out 1060 ms 56620 KB Time limit exceeded
67 Execution timed out 1044 ms 56772 KB Time limit exceeded
68 Execution timed out 1022 ms 56984 KB Time limit exceeded
69 Execution timed out 1063 ms 56700 KB Time limit exceeded
70 Execution timed out 1071 ms 36576 KB Time limit exceeded
71 Execution timed out 1105 ms 56736 KB Time limit exceeded
72 Execution timed out 1096 ms 56620 KB Time limit exceeded
73 Execution timed out 1036 ms 56724 KB Time limit exceeded
74 Execution timed out 1030 ms 56832 KB Time limit exceeded
75 Execution timed out 1035 ms 56828 KB Time limit exceeded
76 Execution timed out 1068 ms 56664 KB Time limit exceeded
77 Execution timed out 1040 ms 56744 KB Time limit exceeded
78 Execution timed out 1069 ms 56740 KB Time limit exceeded
79 Execution timed out 1055 ms 56748 KB Time limit exceeded
80 Execution timed out 1036 ms 56768 KB Time limit exceeded
81 Execution timed out 1068 ms 56756 KB Time limit exceeded
82 Execution timed out 1031 ms 56748 KB Time limit exceeded
83 Execution timed out 1051 ms 56744 KB Time limit exceeded
84 Execution timed out 1044 ms 56916 KB Time limit exceeded
85 Execution timed out 1058 ms 56788 KB Time limit exceeded
86 Execution timed out 1028 ms 56748 KB Time limit exceeded
87 Execution timed out 1070 ms 56748 KB Time limit exceeded
88 Execution timed out 1059 ms 56968 KB Time limit exceeded
89 Execution timed out 1035 ms 56748 KB Time limit exceeded
90 Execution timed out 1050 ms 36576 KB Time limit exceeded
91 Execution timed out 1054 ms 56788 KB Time limit exceeded
92 Execution timed out 1033 ms 56784 KB Time limit exceeded
93 Execution timed out 1029 ms 56856 KB Time limit exceeded
94 Execution timed out 1036 ms 56748 KB Time limit exceeded
95 Execution timed out 1053 ms 56712 KB Time limit exceeded
96 Execution timed out 1031 ms 56704 KB Time limit exceeded
97 Execution timed out 1018 ms 56904 KB Time limit exceeded
98 Execution timed out 1028 ms 56932 KB Time limit exceeded
99 Execution timed out 1055 ms 56828 KB Time limit exceeded
100 Execution timed out 1047 ms 56820 KB Time limit exceeded