Submission #870939

#	Time	Username	Problem	Language	Result	Execution time	Memory
870939		borisAngelov	Maxcomp (info1cup18_maxcomp)	C++17	100 / 100	51 ms	29132 KiB

maxcomp

#include <bits/stdc++.h>

using namespace std;

const int maxn = 1005;
const int inf = 2e9;

int n, m;

int a[maxn][maxn];

int dp1[maxn][maxn];
int dp2[maxn][maxn];
int dp3[maxn][maxn];
int dp4[maxn][maxn];

char s;
int num;

int read()
{
    num = 0;
    s = getchar();

    while (s < '0' || s > '9')
    {
        s = getchar();
    }

    while ('0' <= s && s <= '9')
    {
        num = num * 10 + (s - '0');
        s = getchar();
    }

    return num;
}

void fastIO()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
}

int main()
{
    fastIO();

    n = read();
    m = read();

    for (int i = 1; i <= n; ++i)
    {
        for (int j = 1; j <= m; ++j)
        {
            a[i][j] = read();
        }
    }

    for (int i = 1; i <= n; ++i)
    {
        for (int j = 1; j <= m; ++j)
        {
            dp1[i][j] = -a[i][j] + i + j;

            if (i >= 2)
            {
                dp1[i][j] = max(dp1[i][j], dp1[i - 1][j]);
            }

            if (j >= 2)
            {
                dp1[i][j] = max(dp1[i][j], dp1[i][j - 1]);
            }
        }
    }

    for (int i = 1; i <= n; ++i)
    {
        for (int j = m; j >= 1; --j)
        {
            dp2[i][j] = -a[i][j] + i - j;

            if (i >= 2)
            {
                dp2[i][j] = max(dp2[i][j], dp2[i - 1][j]);
            }

            if (j <= m - 1)
            {
                dp2[i][j] = max(dp2[i][j], dp2[i][j + 1]);
            }
        }
    }

    for (int i = n; i >= 1; --i)
    {
        for (int j = 1; j <= m; ++j)
        {
            dp3[i][j] = -a[i][j] - i + j;

            if (i <= n - 1)
            {
                dp3[i][j] = max(dp3[i][j], dp3[i + 1][j]);
            }

            if (j >= 2)
            {
                dp3[i][j] = max(dp3[i][j], dp3[i][j - 1]);
            }
        }
    }

    for (int i = n; i >= 1; --i)
    {
        for (int j = m; j >= 1; --j)
        {
            dp4[i][j] = -a[i][j] - i - j;

            if (i <= n - 1)
            {
                dp4[i][j] = max(dp4[i][j], dp4[i + 1][j]);
            }

            if (j <= m - 1)
            {
                dp4[i][j] = max(dp4[i][j], dp4[i][j + 1]);
            }
        }
    }

    int ans = -inf;

    for (int i = 1; i <= n; ++i)
    {
        for (int j = 1; j <= m; ++j)
        {
            ans = max(ans, a[i][j] + dp1[i][j] - i - j);
            ans = max(ans, a[i][j] + dp2[i][j] - i + j);
            ans = max(ans, a[i][j] + dp3[i][j] + i - j);
            ans = max(ans, a[i][j] + dp4[i][j] + i + j);
        }
    }

    cout << ans - 1 << endl;

    return 0;
}

• Subtask 1: 15 / 15
• Subtask 2: 15 / 15
• Subtask 3: 30 / 30
• Subtask 4: 40 / 40