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Submission #173169

# Submission time Handle Problem Language Result Execution time Memory
173169 2020-01-03T14:19:40 Z VEGAnn Bomb (IZhO17_bomb) C++14
14 / 100
 1000 ms 104888 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 < 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
14.0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 632 KB Output is correct
3 Correct 61 ms 60620 KB Output is correct
4 Correct 64 ms 60540 KB Output is correct
5 Correct 2 ms 376 KB Output is correct
6 Correct 2 ms 376 KB Output is correct
7 Correct 2 ms 376 KB Output is correct
8 Incorrect 2 ms 632 KB Output isn't correct
9 Incorrect 2 ms 760 KB Output isn't correct
10 Incorrect 2 ms 632 KB Output isn't correct
11 Incorrect 3 ms 760 KB Output isn't correct
12 Incorrect 2 ms 632 KB Output isn't correct
13 Correct 2 ms 632 KB Output is correct
14 Correct 2 ms 632 KB Output is correct
15 Incorrect 2 ms 632 KB Output isn't correct
16 Correct 2 ms 632 KB Output is correct
17 Correct 2 ms 1528 KB Output is correct
18 Incorrect 3 ms 1528 KB Output isn't correct
19 Incorrect 3 ms 1912 KB Output isn't correct
20 Incorrect 3 ms 1912 KB Output isn't correct
21 Incorrect 3 ms 1272 KB Output isn't correct
22 Incorrect 3 ms 1656 KB Output isn't correct
23 Incorrect 4 ms 2040 KB Output isn't correct
24 Incorrect 3 ms 1784 KB Output isn't correct
25 Incorrect 4 ms 2040 KB Output isn't correct
26 Correct 4 ms 2040 KB Output is correct
27 Correct 72 ms 8696 KB Output is correct
28 Incorrect 9 ms 6392 KB Output isn't correct
29 Incorrect 215 ms 11768 KB Output isn't correct
30 Incorrect 220 ms 13752 KB Output isn't correct
31 Incorrect 12 ms 7544 KB Output isn't correct
32 Incorrect 140 ms 12664 KB Output isn't correct
33 Incorrect 260 ms 14456 KB Output isn't correct
34 Incorrect 9 ms 7032 KB Output isn't correct
35 Incorrect 245 ms 14456 KB Output isn't correct
36 Correct 352 ms 14328 KB Output is correct
37 Incorrect 2 ms 632 KB Output isn't correct
38 Execution timed out 1085 ms 102408 KB Time limit exceeded
39 Incorrect 2 ms 636 KB Output isn't correct
40 Execution timed out 1084 ms 30780 KB Time limit exceeded
41 Incorrect 2 ms 760 KB Output isn't correct
42 Incorrect 4 ms 2040 KB Output isn't correct
43 Execution timed out 1095 ms 103192 KB Time limit exceeded
44 Incorrect 306 ms 14456 KB Output isn't correct
45 Execution timed out 1058 ms 102008 KB Time limit exceeded
46 Execution timed out 1084 ms 103616 KB Time limit exceeded
47 Execution timed out 1094 ms 103160 KB Time limit exceeded
48 Execution timed out 1092 ms 103644 KB Time limit exceeded
49 Execution timed out 1092 ms 98680 KB Time limit exceeded
50 Execution timed out 1092 ms 101112 KB Time limit exceeded
51 Execution timed out 1091 ms 101920 KB Time limit exceeded
52 Execution timed out 1076 ms 101760 KB Time limit exceeded
53 Execution timed out 1049 ms 101752 KB Time limit exceeded
54 Execution timed out 1066 ms 101764 KB Time limit exceeded
55 Execution timed out 1030 ms 101868 KB Time limit exceeded
56 Execution timed out 1074 ms 101800 KB Time limit exceeded
57 Execution timed out 1091 ms 101896 KB Time limit exceeded
58 Execution timed out 1085 ms 101756 KB Time limit exceeded
59 Execution timed out 1092 ms 101752 KB Time limit exceeded
60 Execution timed out 1080 ms 101804 KB Time limit exceeded
61 Execution timed out 1074 ms 98560 KB Time limit exceeded
62 Execution timed out 1093 ms 101880 KB Time limit exceeded
63 Execution timed out 1081 ms 101672 KB Time limit exceeded
64 Execution timed out 1071 ms 101696 KB Time limit exceeded
65 Execution timed out 1073 ms 101752 KB Time limit exceeded
66 Execution timed out 1075 ms 101752 KB Time limit exceeded
67 Execution timed out 1073 ms 104268 KB Time limit exceeded
68 Execution timed out 1087 ms 103928 KB Time limit exceeded
69 Execution timed out 1087 ms 103176 KB Time limit exceeded
70 Execution timed out 1086 ms 78964 KB Time limit exceeded
71 Execution timed out 1088 ms 102648 KB Time limit exceeded
72 Execution timed out 1087 ms 102520 KB Time limit exceeded
73 Execution timed out 1092 ms 102316 KB Time limit exceeded
74 Execution timed out 1094 ms 102136 KB Time limit exceeded
75 Execution timed out 1090 ms 102008 KB Time limit exceeded
76 Execution timed out 1090 ms 101752 KB Time limit exceeded
77 Execution timed out 1094 ms 101752 KB Time limit exceeded
78 Execution timed out 1088 ms 101752 KB Time limit exceeded
79 Execution timed out 1070 ms 102380 KB Time limit exceeded
80 Execution timed out 1095 ms 103032 KB Time limit exceeded
81 Execution timed out 1087 ms 103788 KB Time limit exceeded
82 Execution timed out 1089 ms 103800 KB Time limit exceeded
83 Execution timed out 1069 ms 104068 KB Time limit exceeded
84 Execution timed out 1061 ms 104392 KB Time limit exceeded
85 Execution timed out 1081 ms 104696 KB Time limit exceeded
86 Execution timed out 1062 ms 104696 KB Time limit exceeded
87 Execution timed out 1069 ms 104840 KB Time limit exceeded
88 Execution timed out 1073 ms 104844 KB Time limit exceeded
89 Execution timed out 1077 ms 104772 KB Time limit exceeded
90 Execution timed out 1090 ms 79096 KB Time limit exceeded
91 Execution timed out 1075 ms 104888 KB Time limit exceeded
92 Execution timed out 1087 ms 104704 KB Time limit exceeded
93 Execution timed out 1083 ms 101920 KB Time limit exceeded
94 Execution timed out 1082 ms 101672 KB Time limit exceeded
95 Execution timed out 1066 ms 102076 KB Time limit exceeded
96 Execution timed out 1087 ms 103032 KB Time limit exceeded
97 Execution timed out 1081 ms 103196 KB Time limit exceeded
98 Execution timed out 1093 ms 104152 KB Time limit exceeded
99 Execution timed out 1092 ms 103516 KB Time limit exceeded
100 Execution timed out 1075 ms 104684 KB Time limit exceeded