Submission #169921

# Submission time Handle Problem Language Result Execution time Memory
169921 2019-12-23T09:22:05 Z stefdasca Bomb (IZhO17_bomb) C++14
68 / 100
784 ms 59000 KB
#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];
    if(n <= 450 && m <= 450)
    {
        int mxans = 0;
        for(int i = n; i >= 1; --i)
        {
            int st = mxans / i + 1;
            int dr = m;
            if(st > dr)
                break;
            int ans = 0;
            if(chk(i, st))
                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;
    }
    else
    {
        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;
        // mnx * some number
        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 = 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);
        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)
                        ~~^~~~
# 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 28 ms 26872 KB Output is correct
4 Correct 27 ms 26764 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 Correct 2 ms 504 KB Output is correct
9 Correct 2 ms 504 KB Output is correct
10 Correct 2 ms 548 KB Output is correct
11 Correct 2 ms 548 KB Output is correct
12 Correct 2 ms 504 KB Output is correct
13 Correct 2 ms 504 KB Output is correct
14 Correct 2 ms 504 KB Output is correct
15 Correct 2 ms 508 KB Output is correct
16 Correct 2 ms 504 KB Output is correct
17 Correct 3 ms 1016 KB Output is correct
18 Correct 3 ms 1144 KB Output is correct
19 Correct 4 ms 1400 KB Output is correct
20 Correct 4 ms 1400 KB Output is correct
21 Correct 3 ms 988 KB Output is correct
22 Correct 4 ms 1272 KB Output is correct
23 Correct 5 ms 1528 KB Output is correct
24 Correct 4 ms 1272 KB Output is correct
25 Correct 5 ms 1656 KB Output is correct
26 Correct 5 ms 1528 KB Output is correct
27 Correct 51 ms 4220 KB Output is correct
28 Correct 45 ms 4472 KB Output is correct
29 Correct 119 ms 5752 KB Output is correct
30 Correct 115 ms 6520 KB Output is correct
31 Correct 72 ms 5256 KB Output is correct
32 Correct 95 ms 6056 KB Output is correct
33 Correct 140 ms 6904 KB Output is correct
34 Correct 39 ms 4856 KB Output is correct
35 Correct 107 ms 6904 KB Output is correct
36 Correct 177 ms 6908 KB Output is correct
37 Correct 2 ms 632 KB Output is correct
38 Correct 17 ms 7928 KB Output is correct
39 Correct 2 ms 632 KB Output is correct
40 Correct 61 ms 15988 KB Output is correct
41 Correct 2 ms 504 KB Output is correct
42 Correct 7 ms 1656 KB Output is correct
43 Correct 784 ms 58804 KB Output is correct
44 Correct 288 ms 6904 KB Output is correct
45 Incorrect 432 ms 59000 KB Output isn't correct
46 Correct 434 ms 58864 KB Output is correct
47 Incorrect 451 ms 58940 KB Output isn't correct
48 Correct 438 ms 58816 KB Output is correct
49 Correct 367 ms 58872 KB Output is correct
50 Correct 472 ms 58964 KB Output is correct
51 Correct 470 ms 58996 KB Output is correct
52 Correct 454 ms 58804 KB Output is correct
53 Correct 424 ms 58828 KB Output is correct
54 Correct 442 ms 59000 KB Output is correct
55 Correct 424 ms 58872 KB Output is correct
56 Correct 563 ms 58232 KB Output is correct
57 Correct 531 ms 58872 KB Output is correct
58 Correct 535 ms 58616 KB Output is correct
59 Correct 486 ms 58276 KB Output is correct
60 Correct 461 ms 58284 KB Output is correct
61 Correct 477 ms 58284 KB Output is correct
62 Correct 726 ms 58364 KB Output is correct
63 Correct 735 ms 58616 KB Output is correct
64 Correct 617 ms 58360 KB Output is correct
65 Correct 398 ms 58284 KB Output is correct
66 Correct 430 ms 58332 KB Output is correct
67 Correct 437 ms 58360 KB Output is correct
68 Correct 514 ms 58360 KB Output is correct
69 Correct 483 ms 58364 KB Output is correct
70 Incorrect 260 ms 46968 KB Output isn't correct
71 Incorrect 471 ms 58488 KB Output isn't correct
72 Incorrect 475 ms 58504 KB Output isn't correct
73 Incorrect 417 ms 58488 KB Output isn't correct
74 Incorrect 441 ms 58572 KB Output isn't correct
75 Incorrect 454 ms 58616 KB Output isn't correct
76 Incorrect 450 ms 58488 KB Output isn't correct
77 Incorrect 495 ms 58560 KB Output isn't correct
78 Incorrect 479 ms 58588 KB Output isn't correct
79 Incorrect 314 ms 58472 KB Output isn't correct
80 Incorrect 306 ms 58440 KB Output isn't correct
81 Incorrect 355 ms 58488 KB Output isn't correct
82 Incorrect 479 ms 58616 KB Output isn't correct
83 Incorrect 491 ms 58616 KB Output isn't correct
84 Incorrect 282 ms 58616 KB Output isn't correct
85 Incorrect 431 ms 58660 KB Output isn't correct
86 Incorrect 356 ms 58616 KB Output isn't correct
87 Correct 416 ms 58616 KB Output is correct
88 Incorrect 453 ms 58872 KB Output isn't correct
89 Incorrect 468 ms 58616 KB Output isn't correct
90 Incorrect 288 ms 47036 KB Output isn't correct
91 Incorrect 444 ms 58748 KB Output isn't correct
92 Incorrect 452 ms 58744 KB Output isn't correct
93 Incorrect 383 ms 58680 KB Output isn't correct
94 Incorrect 417 ms 58776 KB Output isn't correct
95 Incorrect 527 ms 58744 KB Output isn't correct
96 Incorrect 476 ms 58768 KB Output isn't correct
97 Incorrect 356 ms 58712 KB Output isn't correct
98 Incorrect 533 ms 58744 KB Output isn't correct
99 Incorrect 455 ms 58872 KB Output isn't correct
100 Incorrect 399 ms 58772 KB Output isn't correct