Submission #1162555

#	Time	Username	Problem	Language	Result	Execution time	Memory
1162555		jerzyk	The Kingdom of JOIOI (JOI17_joioi)	C++20	100 / 100	376 ms	94932 KiB

joioi

#include <bits/stdc++.h>

using namespace std;
#define pb push_back
#define st first
#define nd second
typedef long long ll;
typedef long double ld;
const ll I = 1000'000'000'000'000'000LL;
const int II = 2'000'000'000;
const ll M = 1000'000'007LL;
const int N = 2007;
int tab[N][N];
int t1[N][N], t2[N][N];
int m1[N][N], m2[N][N];
int dp[N][N];

void Calc(int n, int m)
{
    for(int i = 1; i <= n; ++i)
        for(int j = 1; j <= m; ++j)
            m1[i][j] = max(t1[i][j], m1[i][j - 1]);
    for(int i = 1; i <= n; ++i)
        for(int j = m; j >= 1; --j)
            m2[i][j] = max(t2[i][j], m2[i][j + 1]);
}

int LiczDP(int n, int m)
{
    Calc(n, m);
    for(int i = 1; i <= n; ++i)
    {
        dp[i][m + 1] = II;
        for(int j = m; j >= 0; --j)
        {
            dp[i][j] = max(dp[i - 1][j], max(m1[i][j], m2[i][j + 1]));
            dp[i][j] = min(dp[i][j], dp[i][j + 1]);
        }
    }
    return dp[n][0];
}

void Solve()
{
    int n, m, mi = II, ma = -1;
    cin >> n >> m;
    for(int i = 1; i <= n; ++i)
        for(int j = 1; j <= m; ++j)
        {
            cin >> tab[i][j];
            mi = min(mi, tab[i][j]);
            ma = max(ma, tab[i][j]);
        }
    for(int i = 1; i <= n; ++i)
        for(int j = 1; j <= m; ++j)
        {
            t1[i][j] = tab[i][j] - mi;
            t2[i][j] = ma - tab[i][j];
        }
    int ans = II;
    for(int r = 0; r < 2; ++r)
    {
        for(int l = 0; l < 2; ++l)
        {
            ans = min(ans, LiczDP(n, m));
            for(int i = 1; i <= n; ++i)
                for(int j = 1; j <= m; ++j)
                    swap(t1[i][j], t2[i][j]);
        }
        for(int i = 1; i <= n; ++i)
            for(int j = 1; j <= m / 2; ++j)
            {
                swap(t1[i][j], t1[i][m - j + 1]);
                swap(t2[i][j], t2[i][m - j + 1]);
            }
    }
    cout << ans << "\n";
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    //int t; cin >> t;
    //while(t--)
        Solve();

    return 0;
}

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