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Submission #173171

# Submission time Handle Problem Language Result Execution time Memory
173171 2020-01-03T14:23:48 Z VEGAnn Bomb (IZhO17_bomb) C++14
16 / 100
 1000 ms 98936 KB 
#include <bits/stdc++.h>
//#pragma GCC optimize("unroll-loops")
//#pragma GCC optimize("-O3")
//#pragma GCC optimize("Ofast")
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define sz(x) ((int)x.size())
#define MP make_pair
#define ft first
#define sd second
#define pii pair<int, int>
#define PB push_back
using namespace std;
using namespace __gnu_pbds;
typedef long double ld;
typedef long long ll;
template <class T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
const int N = 2510;
const int oo = 2e9;
int n, m, ans, a[N][N], mx = oo, pref[N][N];
short pr[N][N], best[N], nt[N][N], down[N][2], up[N][2];
short pl[N][N], vl[N][N];
stack<int> st;

bool ok(int ht, int wd){
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= m; j++)
            pl[i][j] = 0;

    bool was = 1;
    for (int i = 1; i <= n; i++)
    for (int j = 1; j <= m; j++){
        if (i + ht - 1 > n || j + wd - 1 > m)
            break;
        int i1 = i + ht - 1, i2 = i - 1;
        int j1 = j + wd - 1, j2 = j - 1;
        int kol = pref[i1][j1] - pref[i2][j1] - pref[i1][j2] + pref[i2][j2];

        if (kol > 0) continue;

        was = 1;
        pl[i][j]++; pl[i][j + wd]--;
        pl[i + ht][j]--; pl[i + ht][j + wd]++;

    }

    if (!was) return 0;

    for (int i = 1; i <= n; i++){
        int cr = 0;
        for (int j = 1; j <= m; j++){
            cr += pl[i][j];
            vl[i][j] = cr;
        }
    }

    for (int j = 1; j <= m; j++){
        int cr = 0;
        for (int i = 1; i <= n; i++){
            cr += vl[i][j];
            if (a[i][j] == 1 && cr == 0)
                return 0;
        }
    }

    return 1;
}

int main(){
    ios_base::sync_with_stdio(0); cin.tie(0);
//    freopen("in.txt","r",stdin);

    ll sta = chrono::system_clock().now().time_since_epoch().count();

    cin >> n >> m;
    for (int i = 1; i <= n; i++)
    for (int j = 1; j <= m; j++){
        char c; cin >> c;
        a[i][j] = (c == '1' ? 1 : 0);

        pref[i][j] = (a[i][j] ^ 1) + pref[i - 1][j] + pref[i][j - 1] - pref[i - 1][j - 1];

    }

    for (int j = 1; j <= m; j++){
        for (int i = 1; i <= n; ){
            if (a[i][j] == 0)
                i++;
            else {
                int i1 = i;
                while (i1 <= n && a[i1][j] == 1)
                    i1++;
                mx = min(mx, i1 - i);
                i = i1;
            }
        }
    }

    if (mx == oo){
        cout << n * m;
        return 0;
    }

    fill(best, best + n + 1, N);

    for (int i = 1; i <= n; i++){
        int pre = 0;
        for (int j = 1; j <= m; j++){
            if (a[i][j] == 0)
                pre = j;
            pr[i][j] = pre + 1;
        }

        pre = m + 1;
        for (int j = m; j > 0; j--){
            if (a[i][j] == 0)
                pre = j;
            nt[i][j] = pre - 1;
        }
    }

    for (int j = 1; j <= m; j++){
        for (int i = 1; i <= n; ){
            if (a[i][j] == 0)
                i++;
            else {
                int i1 = i;
                while (i1 <= n && a[i1][j] == 1)
                    i1++;

                while (sz(st)) st.pop();
                for (int ii = i; ii < i1; ii++){
                    while (sz(st) && pr[st.top()][j] <= pr[ii][j])
                        st.pop();
                    down[ii][0] = (sz(st) == 0 ? i : st.top() + 1);
                    st.push(ii);
                }

                while (sz(st)) st.pop();
                for (int ii = i; ii < i1; ii++){
                    while (sz(st) && nt[st.top()][j] >= nt[ii][j])
                        st.pop();
                    down[ii][1] = (sz(st) == 0 ? i : st.top() + 1);
                    st.push(ii);
                }

                while (sz(st)) st.pop();
                for (int ii = i1 - 1; ii >= i; ii--){
                    while (sz(st) && pr[st.top()][j] <= pr[ii][j])
                        st.pop();
                    up[ii][0] = (sz(st) == 0 ? i1 - 1 : st.top() - 1);
                    st.push(ii);
                }

                while (sz(st)) st.pop();
                for (int ii = i1 - 1; ii >= i; ii--){
                    while (sz(st) && nt[st.top()][j] >= nt[ii][j])
                        st.pop();
                    up[ii][1] = (sz(st) == 0 ? i1 - 1 : st.top() - 1);
                    st.push(ii);
                }

                i = i1;
            }
        }

        for (int i = 1; i <= n; i++){
            if (a[i][j] == 0) continue;
            int l = max(down[i][0], down[i][1]);
            int r = min(up[i][0], up[i][1]);
            int cur = r - l + 1;
            best[cur] = min(best[cur], short(nt[i][j] - pr[i][j] + 1));
        }
    }

    best[n + 1] = N;
    for (int i = n; i > 0; i--) {
        best[i] = min(best[i + 1], best[i]);
        if (best[i] < N && i <= mx)
            ans = max(ans, best[i] * i);
    }

    int wd = m;
    for (int ht = 1; ht <= n; ht++){
        ll tim = chrono::system_clock().now().time_since_epoch().count();;
        if (tim - sta > int(1e9) - 10000000) break;
        while (wd > 0 && !ok(ht, wd))
            wd--;
        if (wd == 0) break;
        if (n * wd <= ans) break;
        ans = max(ans, ht * wd);
    }

    cout << ans << '\n';

    return 0;
}

Subtask #1
16.0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 888 KB Output is correct
3 Correct 59 ms 60664 KB Output is correct
4 Correct 62 ms 60536 KB Output is correct
5 Correct 14 ms 632 KB Output is correct
6 Correct 4 ms 376 KB Output is correct
7 Correct 2 ms 508 KB Output is correct
8 Incorrect 2 ms 888 KB Output isn't correct
9 Incorrect 2 ms 888 KB Output isn't correct
10 Incorrect 2 ms 760 KB Output isn't correct
11 Incorrect 2 ms 888 KB Output isn't correct
12 Incorrect 3 ms 760 KB Output isn't correct
13 Correct 2 ms 760 KB Output is correct
14 Correct 2 ms 760 KB Output is correct
15 Incorrect 2 ms 760 KB Output isn't correct
16 Correct 2 ms 888 KB Output is correct
17 Correct 4 ms 2040 KB Output is correct
18 Incorrect 5 ms 2168 KB Output isn't correct
19 Incorrect 6 ms 2808 KB Output isn't correct
20 Incorrect 6 ms 2680 KB Output isn't correct
21 Incorrect 4 ms 1656 KB Output isn't correct
22 Incorrect 5 ms 2296 KB Output isn't correct
23 Incorrect 7 ms 2940 KB Output isn't correct
24 Incorrect 5 ms 2424 KB Output isn't correct
25 Incorrect 7 ms 2908 KB Output isn't correct
26 Correct 8 ms 2936 KB Output is correct
27 Correct 72 ms 8696 KB Output is correct
28 Incorrect 98 ms 9180 KB Output isn't correct
29 Incorrect 215 ms 11772 KB Output isn't correct
30 Incorrect 220 ms 13688 KB Output isn't correct
31 Incorrect 162 ms 10744 KB Output isn't correct
32 Incorrect 141 ms 12640 KB Output isn't correct
33 Incorrect 257 ms 14456 KB Output isn't correct
34 Incorrect 55 ms 10236 KB Output isn't correct
35 Incorrect 244 ms 14468 KB Output isn't correct
36 Correct 355 ms 14464 KB Output is correct
37 Incorrect 2 ms 888 KB Output isn't correct
38 Execution timed out 1040 ms 98808 KB Time limit exceeded
39 Incorrect 2 ms 892 KB Output isn't correct
40 Incorrect 980 ms 30812 KB Output isn't correct
41 Incorrect 2 ms 888 KB Output isn't correct
42 Incorrect 7 ms 2936 KB Output isn't correct
43 Execution timed out 1083 ms 98652 KB Time limit exceeded
44 Incorrect 288 ms 14328 KB Output isn't correct
45 Execution timed out 1082 ms 98640 KB Time limit exceeded
46 Execution timed out 1079 ms 98684 KB Time limit exceeded
47 Execution timed out 1087 ms 98608 KB Time limit exceeded
48 Execution timed out 1079 ms 98680 KB Time limit exceeded
49 Correct 977 ms 74156 KB Output is correct
50 Execution timed out 1068 ms 98564 KB Time limit exceeded
51 Execution timed out 1084 ms 98652 KB Time limit exceeded
52 Execution timed out 1082 ms 98684 KB Time limit exceeded
53 Execution timed out 1037 ms 98680 KB Time limit exceeded
54 Execution timed out 1061 ms 98680 KB Time limit exceeded
55 Execution timed out 1076 ms 98644 KB Time limit exceeded
56 Execution timed out 1081 ms 98632 KB Time limit exceeded
57 Execution timed out 1043 ms 98684 KB Time limit exceeded
58 Execution timed out 1074 ms 98564 KB Time limit exceeded
59 Execution timed out 1051 ms 98668 KB Time limit exceeded
60 Execution timed out 1058 ms 98624 KB Time limit exceeded
61 Correct 977 ms 74172 KB Output is correct
62 Execution timed out 1058 ms 98684 KB Time limit exceeded
63 Execution timed out 1079 ms 98632 KB Time limit exceeded
64 Execution timed out 1080 ms 98564 KB Time limit exceeded
65 Execution timed out 1094 ms 98808 KB Time limit exceeded
66 Execution timed out 1093 ms 98716 KB Time limit exceeded
67 Execution timed out 1091 ms 98564 KB Time limit exceeded
68 Execution timed out 1082 ms 98748 KB Time limit exceeded
69 Execution timed out 1093 ms 98684 KB Time limit exceeded
70 Execution timed out 1092 ms 79000 KB Time limit exceeded
71 Execution timed out 1085 ms 98680 KB Time limit exceeded
72 Execution timed out 1096 ms 98564 KB Time limit exceeded
73 Execution timed out 1081 ms 98696 KB Time limit exceeded
74 Execution timed out 1085 ms 98620 KB Time limit exceeded
75 Execution timed out 1089 ms 98736 KB Time limit exceeded
76 Execution timed out 1077 ms 98680 KB Time limit exceeded
77 Execution timed out 1088 ms 98808 KB Time limit exceeded
78 Execution timed out 1079 ms 98680 KB Time limit exceeded
79 Execution timed out 1087 ms 98808 KB Time limit exceeded
80 Execution timed out 1089 ms 98636 KB Time limit exceeded
81 Execution timed out 1078 ms 98680 KB Time limit exceeded
82 Execution timed out 1082 ms 98680 KB Time limit exceeded
83 Execution timed out 1083 ms 98780 KB Time limit exceeded
84 Execution timed out 1092 ms 98680 KB Time limit exceeded
85 Execution timed out 1093 ms 98808 KB Time limit exceeded
86 Execution timed out 1071 ms 98624 KB Time limit exceeded
87 Execution timed out 1076 ms 98808 KB Time limit exceeded
88 Execution timed out 1085 ms 98680 KB Time limit exceeded
89 Execution timed out 1090 ms 98808 KB Time limit exceeded
90 Execution timed out 1087 ms 79096 KB Time limit exceeded
91 Execution timed out 1077 ms 98680 KB Time limit exceeded
92 Execution timed out 1077 ms 98808 KB Time limit exceeded
93 Execution timed out 1084 ms 98676 KB Time limit exceeded
94 Execution timed out 1078 ms 98564 KB Time limit exceeded
95 Execution timed out 1087 ms 98808 KB Time limit exceeded
96 Execution timed out 1079 ms 98936 KB Time limit exceeded
97 Execution timed out 1072 ms 98620 KB Time limit exceeded
98 Execution timed out 1063 ms 98676 KB Time limit exceeded
99 Execution timed out 1089 ms 98792 KB Time limit exceeded
100 Execution timed out 1010 ms 98552 KB Time limit exceeded