Submission #169916

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
169916	2019-12-23T09:17:05 Z	stefdasca	Bomb (IZhO17_bomb)	C++14	46 / 100	559 ms	59640 KB

bomb

#include<bits/stdc++.h>
#define god dimasi5eks
#pragma GCC optimize("O3")
#define fi first
#define se second
#define pb push_back
#define pf push_front
#define mod 1000000007
#define dancila 3.14159265359
#define eps 1e-9

using namespace std;

typedef long long ll;


int add(int a, int b)
{
    ll x = a+b;
    if(x >= mod)
        x -= mod;
    if(x < 0)
        x += mod;
    return x;
}
ll mul(ll a, ll b)
{
    return (a*b) % mod;
}

ll pw(ll a, ll b)
{
    ll ans = 1;
    while(b)
    {
        if(b & 1)
            ans = (ans * a) % mod;
        a = (a * a) % mod;
        b >>= 1;
    }
    return ans;
}
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
long long rand_seed()
{
    long long a = rng();
    return a;
}
char c[2600][2600];
int n, m, mars[2600][2600], sp[2600][2600];
int sum(int xa, int ya, int xb, int yb)
{
    return sp[xb][yb] - sp[xa - 1][yb] - sp[xb][ya - 1] + sp[xa - 1][ya - 1];
}
bool chk(int i, int j)
{
    for(int q = i; q <= n; ++q)
        for(int p = j; p <= m; ++p)
        {
            if(sp[q][p] - sp[q - i][p] - sp[q][p - j] + sp[q - i][p - j] == i * j)
            {
                mars[q - i + 1][p - j + 1]++;
                mars[q + 1][p - j + 1]--;
                mars[q - i + 1][p + 1]--;
                mars[q + 1][p + 1]++;
            }
        }
    bool ok = 1;
    for(int q = 1; q <= n; ++q)
        for(int p = 1; p <= m; ++p)
        {
            mars[q][p] = mars[q][p] + mars[q-1][p] + mars[q][p-1] - mars[q-1][p-1];
            if(c[q][p] == '1' && !mars[q][p])
            {
                ok = 0;
                p = m+1;
                q = n+1;
            }
        }
    for(int q = 1; q <= n; ++q)
        for(int p = 1; p <= m; ++p)
            mars[q][p] = 0;
    return ok;
}
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cin >> n >> m;
    for(int i = 1; i <= n; ++i)
        cin >> (c[i] + 1);
    int xx = 0;
    for(int i = 1; i <= n; ++i)
        for(int j = 1; j <= m; ++j)
            xx += (c[i][j] == '0');
    if(!xx)
    {
        cout << n*m;
        return 0;
    }
    for(int i = 1; i <= n; ++i)
        for(int j = 1; j <= m; ++j)
            sp[i][j] = (c[i][j] - '0') + sp[i-1][j] + sp[i][j-1] - sp[i-1][j-1];
    int mnx = m, mny = n;
    for(int i = 1; i <= n; ++i)
    {
        int str = 0;
        for(int j = 1; j <= m; ++j)
        {
            if(c[i][j] == '1')
                ++str;
            else
            {
                if(str)
                    mnx = min(mnx, str);
                str = 0;
            }
        }
        if(str)
            mnx = min(mnx, str);
    }
    for(int j = 1; j <= m; ++j)
    {
        int str = 0;
        for(int i = 1; i <= n; ++i)
        {
            if(c[i][j] == '1')
                ++str;
            else
            {
                if(str)
                    mny = min(mny, str);
                str = 0;
            }
        }
        if(str)
            mny = min(mny, str);
    }
    int mxans = 0;
    int st = 1;
    int dr = mny;
    int ans = 1;
    while(st <= dr)
    {
        int mid = (st + dr) / 2;
        if(chk(mid, mnx))
            ans = mid, st = mid + 1;
        else
            dr = mid - 1;
    }
    mxans = max(mxans, ans * mnx);
    st = mxans / mny + 1;
    dr = mnx;
    ans = 1;
    while(st <= dr)
    {
        int mid = (st + dr) / 2;
        if(chk(mny, mid))
            ans = mid, st = mid + 1;
        else
            dr = mid - 1;
    }
    mxans = max(mxans, mny * ans);
    if(n <= 450 && m <= 450)
    {
        int mxans = 0;
        for(int i = mny; i >= 1; --i)
        {
            if(i * m <= mxans)
                break;
            int st = mxans / i + 1;
            int dr = m;
            int ans = 0;
            while(st <= dr)
            {
                int mid = (st + dr) / 2;
                if(chk(i, mid))
                    ans = mid, st = mid + 1;
                else
                    dr = mid - 1;
            }
            mxans = max(mxans, i * ans);
        }
    }
    cout << mxans;
    return 0;
}

Compilation message

bomb.cpp: In function 'bool chk(int, int)':
bomb.cpp:70:26: warning: assuming signed overflow does not occur when assuming that (X + c) >= X is always true [-Wstrict-overflow]
         for(int p = 1; p <= m; ++p)
                        ~~^~~~

Subtask #1

46.0 / 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	27 ms	26744 KB	Output is correct
4	Correct	27 ms	26872 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	504 KB	Output isn't correct
10	Correct	2 ms	504 KB	Output is correct
11	Incorrect	2 ms	632 KB	Output isn't correct
12	Correct	2 ms	508 KB	Output is correct
13	Correct	2 ms	504 KB	Output is correct
14	Correct	2 ms	504 KB	Output is correct
15	Incorrect	2 ms	604 KB	Output isn't correct
16	Correct	2 ms	632 KB	Output is correct
17	Correct	3 ms	1016 KB	Output is correct
18	Incorrect	3 ms	1144 KB	Output isn't correct
19	Incorrect	5 ms	1400 KB	Output isn't correct
20	Incorrect	5 ms	1400 KB	Output isn't correct
21	Incorrect	3 ms	1016 KB	Output isn't correct
22	Incorrect	3 ms	1272 KB	Output isn't correct
23	Incorrect	5 ms	1528 KB	Output isn't correct
24	Incorrect	4 ms	1272 KB	Output isn't correct
25	Incorrect	8 ms	1528 KB	Output isn't correct
26	Correct	5 ms	1528 KB	Output is correct
27	Correct	9 ms	4344 KB	Output is correct
28	Incorrect	19 ms	4344 KB	Output isn't correct
29	Incorrect	140 ms	5752 KB	Output isn't correct
30	Incorrect	350 ms	6648 KB	Output isn't correct
31	Incorrect	188 ms	5240 KB	Output isn't correct
32	Incorrect	292 ms	6056 KB	Output isn't correct
33	Incorrect	534 ms	7032 KB	Output isn't correct
34	Incorrect	18 ms	4860 KB	Output isn't correct
35	Incorrect	69 ms	6904 KB	Output isn't correct
36	Correct	243 ms	6940 KB	Output is correct
37	Correct	3 ms	504 KB	Output is correct
38	Correct	19 ms	7416 KB	Output is correct
39	Correct	3 ms	632 KB	Output is correct
40	Correct	50 ms	15836 KB	Output is correct
41	Correct	2 ms	632 KB	Output is correct
42	Incorrect	7 ms	1528 KB	Output isn't correct
43	Correct	406 ms	58488 KB	Output is correct
44	Incorrect	555 ms	6904 KB	Output isn't correct
45	Incorrect	413 ms	58360 KB	Output isn't correct
46	Correct	264 ms	58232 KB	Output is correct
47	Incorrect	412 ms	58360 KB	Output isn't correct
48	Correct	433 ms	58232 KB	Output is correct
49	Correct	211 ms	58500 KB	Output is correct
50	Correct	461 ms	58436 KB	Output is correct
51	Correct	472 ms	58460 KB	Output is correct
52	Correct	446 ms	58416 KB	Output is correct
53	Correct	430 ms	58548 KB	Output is correct
54	Correct	436 ms	58360 KB	Output is correct
55	Correct	418 ms	58464 KB	Output is correct
56	Correct	398 ms	58232 KB	Output is correct
57	Correct	456 ms	58456 KB	Output is correct
58	Correct	525 ms	58616 KB	Output is correct
59	Correct	479 ms	58232 KB	Output is correct
60	Correct	273 ms	58212 KB	Output is correct
61	Correct	281 ms	58360 KB	Output is correct
62	Correct	420 ms	57976 KB	Output is correct
63	Correct	401 ms	58232 KB	Output is correct
64	Correct	350 ms	58204 KB	Output is correct
65	Correct	383 ms	58232 KB	Output is correct
66	Correct	437 ms	58360 KB	Output is correct
67	Correct	469 ms	58232 KB	Output is correct
68	Correct	510 ms	58232 KB	Output is correct
69	Correct	496 ms	58232 KB	Output is correct
70	Incorrect	249 ms	46584 KB	Output isn't correct
71	Incorrect	430 ms	57976 KB	Output isn't correct
72	Incorrect	437 ms	58108 KB	Output isn't correct
73	Incorrect	416 ms	58076 KB	Output isn't correct
74	Incorrect	409 ms	57976 KB	Output isn't correct
75	Incorrect	414 ms	58104 KB	Output isn't correct
76	Incorrect	430 ms	58104 KB	Output isn't correct
77	Incorrect	452 ms	58068 KB	Output isn't correct
78	Incorrect	449 ms	58160 KB	Output isn't correct
79	Incorrect	315 ms	58232 KB	Output isn't correct
80	Incorrect	310 ms	58320 KB	Output isn't correct
81	Incorrect	357 ms	58280 KB	Output isn't correct
82	Incorrect	483 ms	59000 KB	Output isn't correct
83	Incorrect	507 ms	59004 KB	Output isn't correct
84	Incorrect	251 ms	59000 KB	Output isn't correct
85	Incorrect	434 ms	59256 KB	Output isn't correct
86	Incorrect	332 ms	59640 KB	Output isn't correct
87	Correct	400 ms	59256 KB	Output is correct
88	Incorrect	478 ms	59056 KB	Output isn't correct
89	Incorrect	387 ms	59328 KB	Output isn't correct
90	Incorrect	268 ms	47832 KB	Output isn't correct
91	Incorrect	559 ms	59456 KB	Output isn't correct
92	Incorrect	476 ms	59000 KB	Output isn't correct
93	Incorrect	375 ms	59256 KB	Output isn't correct
94	Incorrect	425 ms	59000 KB	Output isn't correct
95	Incorrect	489 ms	59176 KB	Output isn't correct
96	Incorrect	459 ms	59100 KB	Output isn't correct
97	Incorrect	325 ms	59248 KB	Output isn't correct
98	Incorrect	493 ms	59128 KB	Output isn't correct
99	Incorrect	403 ms	59256 KB	Output isn't correct
100	Incorrect	375 ms	59256 KB	Output isn't correct