Submission #456317

# Submission time Handle Problem Language Result Execution time Memory
456317 2021-08-06T11:56:02 Z dxz05 Bomb (IZhO17_bomb) C++14
44 / 100
1000 ms 55940 KB
#pragma GCC optimize("Ofast,O2,O3")
#pragma GCC target("avx2")

#include <bits/stdc++.h>

using namespace std;

void debug_out() { cerr << endl; }

template<typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
    cerr << "[" << H << "]";
    debug_out(T...);
}

#ifdef dddxxz
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#else
#define debug(...) 42
#endif

#define SZ(s) ((int)s.size())
#define all(x) (x).begin(), (x).end()
#define revall(x) (x).rbegin(), (x).rend()

clock_t startTime;

double getCurrentTime() {
    return (double) (clock() - startTime) / CLOCKS_PER_SEC;
}

#define MP make_pair

typedef long long ll;
mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
const double eps = 0.00001;
const int MOD = 1e9;
const int INF = 1000000101;
const long long LLINF = 1223372000000000555;
const int N = 2e6 + 3e2;
const int M = 2522;

int n, m;
int a[M][M];
bool bomb[M][M];
int dp[M][M];

int sum(int x1, int y1, int x2, int y2){
    if (min({x1, y1, x2, y2}) < 1 || max(x1, x2) > n || max(y1, y2) > m) return -1;
    assert(x1 <= x2 && y1 <= y2);
    int res = dp[x2][y2];
    res -= dp[x1 - 1][y2];
    res -= dp[x2][y1 - 1];
    res += dp[x1 - 1][y1 - 1];
    return res;
}

int ans = 0;

bool fill(int x1, int y1, int x2, int y2){
    if (sum(x1, y1, x2, y2) != (x2 - x1 + 1) * (y2 - y1 + 1)) return false;
    for (int i = x1; i <= x2; i++){
        for (int j = y1; j <= y2; j++){
            bomb[i][j] = true;
        }
    }
    return true;
}

bool check(int A, int B){
   // if (ans > A * B) return true;

    for (int i = 1; i <= n; i++){
        for (int j = 1; j <= m; j++) bomb[i][j] = false;
    }

    for (int i = 1; i <= n - A + 1; i++){
        for (int j = 1; j <= m - B + 1; j++){
            if (!a[i][j] || bomb[i][j]) continue;
            fill(i, j, i + A - 1, j + B - 1);
        }
    }

    for (int i = 1; i <= n; i++){
        for (int j = 1; j <= m; j++){
            if (!a[i][j] || bomb[i][j]) continue;
            if (fill(i, j, i + A - 1, j + B - 1)) continue;
            if (fill(i - A + 1, j, i, j + B - 1)) continue;
            if (fill(i, j - B + 1, i + A - 1, j)) continue;
            if (fill(i - A + 1, j - B + 1, i, j)) continue;
            return false;
        }
    }

    ans = max(ans, A * B);

    return true;
}

void solve(int TC) {
    cin >> n >> m;

    for (int i = 1; i <= n; i++){
        for (int j = 1; j <= m; j++){
            char ch;
            cin >> ch;
            a[i][j] = ch - '0';
            dp[i][j] = dp[i][j - 1] + a[i][j];
        }
    }

    for (int j = 1; j <= m; j++){
        for (int i = 1; i <= n; i++){
            dp[i][j] += dp[i - 1][j];
        }
    }

    int A = n, B = m;
    for (int j = 1; j <= m; j++){
        for (int i = 1; i <= n; i++){
            if (a[i][j] == 0) continue;
            int k = i;
            while (k <= n && a[k][j] == 1) k++;
            A = min(A, k - i);
            i = k - 1;
        }
    }

    for (int i = 1; i <= n; i++){
        for (int j = 1; j <= m; j++){
            if (a[i][j] == 0) continue;
            int k = j;
            while (k <= m && a[i][k] == 1) k++;
            B = min(B, k - j);
            j = k - 1;
        }
    }

    if (check(A, B)){
        cout << ans;
        return;
    }

    if (A < B){
        for (int i = 1; i <= A; i++){
            int l = 1, r = B;
            while (l <= r){
                int mid = (l + r) >> 1;
                if (check(i, mid)){
                    l = mid + 1;
                } else r = mid - 1;
            }
        }
    } else {
        for (int i = 1; i <= B; i++){
            int l = 1, r = A;
            while (l <= r){
                int mid = (l + r) >> 1;
                if (check(mid, i)){
                    l = mid + 1;
                } else r = mid - 1;
            }
        }
    }

    cout << ans;

}

int main() {
    startTime = clock();
    cin.tie(nullptr);
    cout.tie(nullptr);
    ios_base::sync_with_stdio(false);

    bool llololcal = false;
#ifdef dddxxz
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
    llololcal = true;
#endif

    int TC = 1;
    //cin >> TC;

    for (int test = 1; test <= TC; test++) {
        debug(test);
        //cout << "Case #" << test << ": ";
        solve(test);
    }

    if (llololcal) cerr << endl << "Time: " << int(getCurrentTime() * 1000) << " ms" << endl;

    return 0;
}

Compilation message

bomb.cpp: In function 'int main()':
bomb.cpp:19:20: warning: statement has no effect [-Wunused-value]
   19 | #define debug(...) 42
      |                    ^~
bomb.cpp:187:9: note: in expansion of macro 'debug'
  187 |         debug(test);
      |         ^~~~~
# Verdict Execution time Memory Grader output
1 Correct 0 ms 332 KB Output is correct
2 Correct 1 ms 460 KB Output is correct
3 Correct 13 ms 26536 KB Output is correct
4 Correct 14 ms 26572 KB Output is correct
5 Correct 1 ms 332 KB Output is correct
6 Correct 1 ms 332 KB Output is correct
7 Correct 1 ms 332 KB Output is 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 0 ms 460 KB Output is correct
14 Correct 1 ms 460 KB Output is correct
15 Correct 1 ms 460 KB Output is correct
16 Correct 1 ms 460 KB Output is correct
17 Incorrect 1 ms 972 KB Output isn't correct
18 Correct 1 ms 1100 KB Output is correct
19 Incorrect 3 ms 1356 KB Output isn't correct
20 Incorrect 3 ms 1356 KB Output isn't correct
21 Correct 1 ms 844 KB Output is correct
22 Correct 2 ms 1100 KB Output is correct
23 Correct 6 ms 1356 KB Output is correct
24 Correct 3 ms 1228 KB Output is correct
25 Correct 9 ms 1356 KB Output is correct
26 Correct 1 ms 1356 KB Output is correct
27 Correct 4 ms 4044 KB Output is correct
28 Correct 14 ms 4240 KB Output is correct
29 Correct 566 ms 5444 KB Output is correct
30 Correct 611 ms 6308 KB Output is correct
31 Correct 305 ms 4996 KB Output is correct
32 Correct 197 ms 5800 KB Output is correct
33 Execution timed out 1087 ms 6604 KB Time limit exceeded
34 Correct 12 ms 4684 KB Output is correct
35 Correct 63 ms 6624 KB Output is correct
36 Correct 8 ms 6604 KB Output is correct
37 Correct 1 ms 460 KB Output is correct
38 Correct 204 ms 55844 KB Output is correct
39 Correct 1 ms 460 KB Output is correct
40 Execution timed out 1090 ms 15428 KB Time limit exceeded
41 Incorrect 1 ms 460 KB Output isn't correct
42 Correct 23 ms 1460 KB Output is correct
43 Correct 496 ms 55908 KB Output is correct
44 Execution timed out 1088 ms 6604 KB Time limit exceeded
45 Execution timed out 1093 ms 55744 KB Time limit exceeded
46 Correct 213 ms 55748 KB Output is correct
47 Execution timed out 1091 ms 55816 KB Time limit exceeded
48 Execution timed out 1093 ms 55876 KB Time limit exceeded
49 Correct 218 ms 55836 KB Output is correct
50 Execution timed out 1093 ms 55836 KB Time limit exceeded
51 Execution timed out 1088 ms 55816 KB Time limit exceeded
52 Execution timed out 1092 ms 55876 KB Time limit exceeded
53 Execution timed out 1093 ms 55732 KB Time limit exceeded
54 Execution timed out 1087 ms 55752 KB Time limit exceeded
55 Execution timed out 1080 ms 55812 KB Time limit exceeded
56 Correct 226 ms 55752 KB Output is correct
57 Execution timed out 1073 ms 55804 KB Time limit exceeded
58 Execution timed out 1081 ms 55748 KB Time limit exceeded
59 Execution timed out 1095 ms 55876 KB Time limit exceeded
60 Correct 212 ms 55748 KB Output is correct
61 Execution timed out 1085 ms 55876 KB Time limit exceeded
62 Correct 235 ms 55760 KB Output is correct
63 Correct 205 ms 55940 KB Output is correct
64 Correct 209 ms 55748 KB Output is correct
65 Execution timed out 1087 ms 55764 KB Time limit exceeded
66 Execution timed out 1088 ms 55748 KB Time limit exceeded
67 Execution timed out 1095 ms 55748 KB Time limit exceeded
68 Execution timed out 1090 ms 55748 KB Time limit exceeded
69 Execution timed out 1093 ms 55716 KB Time limit exceeded
70 Execution timed out 1092 ms 44612 KB Time limit exceeded
71 Execution timed out 1087 ms 55748 KB Time limit exceeded
72 Execution timed out 1093 ms 55748 KB Time limit exceeded
73 Execution timed out 1088 ms 55816 KB Time limit exceeded
74 Execution timed out 1090 ms 55808 KB Time limit exceeded
75 Execution timed out 1089 ms 55816 KB Time limit exceeded
76 Execution timed out 1092 ms 55808 KB Time limit exceeded
77 Execution timed out 1093 ms 55856 KB Time limit exceeded
78 Execution timed out 1082 ms 55788 KB Time limit exceeded
79 Execution timed out 1097 ms 55772 KB Time limit exceeded
80 Execution timed out 1100 ms 55800 KB Time limit exceeded
81 Execution timed out 1100 ms 55744 KB Time limit exceeded
82 Execution timed out 1100 ms 55748 KB Time limit exceeded
83 Execution timed out 1103 ms 55712 KB Time limit exceeded
84 Execution timed out 1097 ms 55808 KB Time limit exceeded
85 Execution timed out 1101 ms 55752 KB Time limit exceeded
86 Execution timed out 1097 ms 55780 KB Time limit exceeded
87 Execution timed out 1090 ms 55804 KB Time limit exceeded
88 Execution timed out 1102 ms 55916 KB Time limit exceeded
89 Execution timed out 1093 ms 55800 KB Time limit exceeded
90 Execution timed out 1093 ms 44732 KB Time limit exceeded
91 Execution timed out 1096 ms 55820 KB Time limit exceeded
92 Execution timed out 1093 ms 55748 KB Time limit exceeded
93 Execution timed out 1094 ms 55760 KB Time limit exceeded
94 Execution timed out 1103 ms 55744 KB Time limit exceeded
95 Execution timed out 1088 ms 55740 KB Time limit exceeded
96 Execution timed out 1096 ms 55836 KB Time limit exceeded
97 Execution timed out 1094 ms 55824 KB Time limit exceeded
98 Execution timed out 1096 ms 55748 KB Time limit exceeded
99 Execution timed out 1085 ms 55872 KB Time limit exceeded
100 Execution timed out 1094 ms 55776 KB Time limit exceeded