Submission #995127

#	Time	Username	Problem	Language	Result	Execution time	Memory
995127		_callmelucian	The Kingdom of JOIOI (JOI17_joioi)	C++14	60 / 100	4019 ms	137516 KiB

joioi

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef long double ld;
typedef pair<ll,ll> pl;
typedef pair<int,int> pii;
typedef tuple<int,int,int> tt;

#define all(a) a.begin(), a.end()
#define filter(a) a.erase(unique(all(a)), a.end())

const int mn = 4e6;
int lo[2001][2001], hi[2001][2001], vec[2][2001][2001];
int calcLo[mn], calcHi[mn], prod;
pii coor[mn];

int get (int arr, pii it) {
    return vec[arr][it.first][it.second];
}

bool check (int arr, int delta) {
    int pos = -1, curLo = INT_MAX, curHi = INT_MIN;
    for (int k = 0; k < prod; k++) {
        int cur = get(arr, coor[k]);
        while (pos + 1 < prod && get(arr, coor[pos + 1]) < cur - delta) {
            int row, col; tie(row, col) = coor[++pos];
            curLo = min(curLo, lo[row][col]);
            curHi = max(curHi, hi[row][col]);
        }
        if (k + 1 < prod && get(arr, coor[k]) == get(arr, coor[k + 1])) continue;
        int cHi = max(calcHi[k], curHi);
        int cLo = min(calcLo[k], curLo);
        if (cHi == INT_MIN || cHi - cLo <= delta) return 1;
    }
    return 0;
}

int solve (int arr, int n, int m) {
    for (int i = 1; i <= n; i++)
        lo[i][0] = INT_MAX, hi[i][0] = INT_MIN;
    for (int j = 1; j <= m; j++) {
        int loCol = INT_MAX, hiCol = INT_MIN;
        for (int i = n; i >= 1; i--) {
            lo[i][j] = min(lo[i][j - 1], loCol = min(loCol, vec[arr][i][j]));
            hi[i][j] = max(hi[i][j - 1], hiCol = max(hiCol, vec[arr][i][j]));
        }
    }

    int counter = 0;
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= m; j++)
            coor[counter++] = make_pair(i, j);

    function<bool(pii a, pii b)> comp = [&] (pii a, pii b) {
        return get(arr, a) < get(arr, b);
    };
    sort(coor, coor + prod, comp);

    int curLo = INT_MAX, curHi = INT_MIN;
    for (int k = prod - 1; k >= 0; k--) {
        calcLo[k] = curLo, calcHi[k] = curHi;
        int row, col; tie(row, col) = coor[k];
        curLo = min(curLo, lo[row][col]);
        curHi = max(curHi, hi[row][col]);
    }

    if (check(arr, 0)) return 0;
    int ans = 0;
    for (int i = 29; i >= 0; i--)
        if (!check(arr, ans | (1 << i))) ans |= (1 << i);
    return ans + 1;
}

int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);

    int n, m; cin >> n >> m;
    prod = n * m;
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= m; j++) {
            cin >> vec[0][i][j];
            vec[1][j][n - i + 1] = vec[0][i][j];
        }
    }


    cout << min(solve(0, n, m), solve(1, m, n));

    return 0;
}

• Subtask 1: 15 / 15
• Subtask 2: 45 / 45
• Subtask 3: 0 / 40