Submission #1051644

#	Time	Username	Problem	Language	Result	Execution time	Memory
1051644		SamAnd	The Kingdom of JOIOI (JOI17_joioi)	C++17	100 / 100	847 ms	54868 KiB

joioi

#include <bits/stdc++.h>
using namespace std;
#define m_p make_pair
#define all(x) (x).begin(),(x).end()
#define sz(x) ((int)(x).size())
#define fi first
#define se second
typedef long long ll;
mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());
mt19937 rnf(2106);
const int N = 2003;
const int INF = 1000000009;

int n, m;
int a[N][N];

bool stg(int x, int y, int z)
{
    int maxu = 0;
    for (int i = 1; i <= n; ++i)
    {
        for (int j = 1; j <= m; ++j)
            maxu = max(maxu, a[i][j]);
    }
    if (maxu - a[x][y] <= z)
        return true;

    int min1 = a[x][y];
    int max1 = 0;
    int min2 = INF;
    int max2 = 0;
    int l = y;
    int r = m;
    for (int i = 1; i <= n; ++i)
    {
        if (l > r)
            return false;
        for (int j = 1; j <= l; ++j)
        {
            max1 = max(max1, a[i][j]);
        }
        for (int j = l + 1; j <= r; ++j)
        {
            if (a[i][j] - min1 > z)
            {
                r = j - 1;
                break;
            }
            max1 = max(max1, a[i][j]);
        }
        for (int j = r + 1; j <= m; ++j)
        {
            min2 = min(min2, a[i][j]);
            max2 = max(max2, a[i][j]);
        }
        if (i == x)
        {
            l = 0;
        }
    }

    return (max1 - min1 <= z && max2 - min2 <= z);
}

int solvv()
{
    int mini = 1;
    int minj = 1;
    for (int i = 1; i <= n; ++i)
    {
        for (int j = 1; j <= m; ++j)
        {
            if (a[i][j] < a[mini][minj])
            {
                mini = i;
                minj = j;
            }
        }
    }

    if (mini == n && minj == m)
        return INF;

    int l = 0, r = INF;
    int ans;
    while (l <= r)
    {
        int m = (l + r) / 2;
        if (stg(mini, minj, m))
        {
            ans = m;
            r = m - 1;
        }
        else
            l = m + 1;
    }

    return ans;
}

void frt()
{
    for (int i = 1; i <= n; ++i)
    {
        reverse(a[i] + 1, a[i] + m + 1);
    }
}
void frs()
{
    for (int j = 1; j <= m; ++j)
    {
        vector<int> v;
        for (int i = 1; i <= n; ++i)
            v.push_back(a[i][j]);
        reverse(all(v));
        for (int i = 1; i <= n; ++i)
            a[i][j] = v[i - 1];
    }
}

void solv()
{
    cin >> n >> m;
    for (int i = 1; i <= n; ++i)
    {
        for (int j = 1; j <= m; ++j)
            cin >> a[i][j];
    }

    int ans = solvv();
    frt();
    ans = min(ans, solvv());
    frs();
    ans = min(ans, solvv());
    frt();
    ans = min(ans, solvv());

    cout << ans << "\n";
}

int main()
{
    #ifdef SOMETHING
    freopen("input.txt", "r", stdin);
    //freopen("output.txt", "w", stdout);
    #endif // SOMETHING
    ios_base::sync_with_stdio(false), cin.tie(0);

    int tt = 1;
    //cin >> tt;
    while (tt--)
    {
        solv();
    }
    return 0;
}

Compilation message (stderr)

joioi.cpp: In function 'int solvv()':
joioi.cpp:85:9: warning: 'ans' may be used uninitialized in this function [-Wmaybe-uninitialized]
   85 |     int ans;
      |         ^~~

• Subtask 1: 15 / 15
• Subtask 2: 45 / 45
• Subtask 3: 40 / 40