oj.uz

Submission #456434

# Submission time Handle Problem Language Result Execution time Memory
456434 2021-08-06T17:35:54 Z dxz05 Bomb (IZhO17_bomb) C++14
50 / 100
 1000 ms 57220 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 = n; i >= A; i--){
        for (int j = 1; j <= m - B + 1; j++){
            if (!a[i][j] || bomb[i][j]) continue;
            fill(i - A + 1, j, i, j + B - 1);
        }
    }

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

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

    for (int i = 1; i <= n; i++){
        for (int j = 1; j <= m; j++){
            if (a[i][j] && !bomb[i][j]) 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:203:9: note: in expansion of macro 'debug'
  203 |         debug(test);
      |         ^~~~~

Subtask #1
50.0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 332 KB Output is correct
2 Correct 1 ms 460 KB Output is correct
3 Correct 13 ms 26572 KB Output is correct
4 Correct 13 ms 26484 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 1 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 Correct 1 ms 972 KB Output is correct
18 Correct 1 ms 1100 KB Output is correct
19 Correct 4 ms 1292 KB Output is correct
20 Correct 4 ms 1372 KB Output is correct
21 Correct 1 ms 844 KB Output is correct
22 Correct 2 ms 1096 KB Output is correct
23 Correct 7 ms 1356 KB Output is correct
24 Correct 3 ms 1228 KB Output is correct
25 Correct 10 ms 1356 KB Output is correct
26 Correct 1 ms 1356 KB Output is correct
27 Correct 5 ms 4044 KB Output is correct
28 Correct 17 ms 4360 KB Output is correct
29 Correct 277 ms 5512 KB Output is correct
30 Correct 581 ms 6476 KB Output is correct
31 Correct 307 ms 5068 KB Output is correct
32 Correct 264 ms 5864 KB Output is correct
33 Correct 781 ms 6732 KB Output is correct
34 Correct 16 ms 4684 KB Output is correct
35 Correct 101 ms 6824 KB Output is correct
36 Correct 9 ms 6728 KB Output is correct
37 Correct 1 ms 460 KB Output is correct
38 Correct 191 ms 57000 KB Output is correct
39 Correct 1 ms 460 KB Output is correct
40 Execution timed out 1087 ms 15988 KB Time limit exceeded
41 Correct 1 ms 460 KB Output is correct
42 Correct 11 ms 1472 KB Output is correct
43 Correct 300 ms 57160 KB Output is correct
44 Execution timed out 1084 ms 6852 KB Time limit exceeded
45 Execution timed out 1082 ms 56968 KB Time limit exceeded
46 Correct 241 ms 57100 KB Output is correct
47 Execution timed out 1080 ms 57048 KB Time limit exceeded
48 Execution timed out 1036 ms 57028 KB Time limit exceeded
49 Correct 242 ms 57048 KB Output is correct
50 Execution timed out 1078 ms 57140 KB Time limit exceeded
51 Execution timed out 1076 ms 57028 KB Time limit exceeded
52 Execution timed out 1080 ms 57028 KB Time limit exceeded
53 Execution timed out 1082 ms 56900 KB Time limit exceeded
54 Execution timed out 1084 ms 56900 KB Time limit exceeded
55 Execution timed out 1074 ms 56900 KB Time limit exceeded
56 Correct 212 ms 56896 KB Output is correct
57 Execution timed out 1078 ms 56904 KB Time limit exceeded
58 Execution timed out 1053 ms 56992 KB Time limit exceeded
59 Execution timed out 1067 ms 57028 KB Time limit exceeded
60 Correct 238 ms 57056 KB Output is correct
61 Correct 240 ms 57152 KB Output is correct
62 Correct 221 ms 57156 KB Output is correct
63 Correct 214 ms 57124 KB Output is correct
64 Correct 229 ms 56916 KB Output is correct
65 Execution timed out 1079 ms 56900 KB Time limit exceeded
66 Execution timed out 1079 ms 56944 KB Time limit exceeded
67 Execution timed out 1057 ms 57044 KB Time limit exceeded
68 Execution timed out 1077 ms 56984 KB Time limit exceeded
69 Execution timed out 1072 ms 57008 KB Time limit exceeded
70 Execution timed out 1093 ms 45132 KB Time limit exceeded
71 Execution timed out 1074 ms 57192 KB Time limit exceeded
72 Execution timed out 1062 ms 57220 KB Time limit exceeded
73 Execution timed out 1072 ms 57036 KB Time limit exceeded
74 Execution timed out 1073 ms 57064 KB Time limit exceeded
75 Execution timed out 1075 ms 57028 KB Time limit exceeded
76 Execution timed out 1090 ms 56764 KB Time limit exceeded
77 Execution timed out 1080 ms 56816 KB Time limit exceeded
78 Execution timed out 1048 ms 56772 KB Time limit exceeded
79 Execution timed out 1059 ms 56772 KB Time limit exceeded
80 Execution timed out 1088 ms 56904 KB Time limit exceeded
81 Execution timed out 1082 ms 57144 KB Time limit exceeded
82 Execution timed out 1073 ms 57028 KB Time limit exceeded
83 Execution timed out 1075 ms 57032 KB Time limit exceeded
84 Execution timed out 1076 ms 57028 KB Time limit exceeded
85 Execution timed out 1075 ms 57032 KB Time limit exceeded
86 Execution timed out 1076 ms 57028 KB Time limit exceeded
87 Execution timed out 1078 ms 57208 KB Time limit exceeded
88 Execution timed out 1078 ms 57096 KB Time limit exceeded
89 Execution timed out 1080 ms 57088 KB Time limit exceeded
90 Execution timed out 1092 ms 45148 KB Time limit exceeded
91 Execution timed out 1078 ms 57028 KB Time limit exceeded
92 Execution timed out 1075 ms 57096 KB Time limit exceeded
93 Execution timed out 1077 ms 57028 KB Time limit exceeded
94 Execution timed out 1067 ms 57024 KB Time limit exceeded
95 Execution timed out 1079 ms 57092 KB Time limit exceeded
96 Execution timed out 1076 ms 57084 KB Time limit exceeded
97 Execution timed out 1075 ms 57120 KB Time limit exceeded
98 Execution timed out 1085 ms 57092 KB Time limit exceeded
99 Execution timed out 1081 ms 57104 KB Time limit exceeded
100 Execution timed out 1070 ms 57116 KB Time limit exceeded