Submission #685110

#	Time	Username	Problem	Language	Result	Execution time	Memory
685110		coffee5427	The Kingdom of JOIOI (JOI17_joioi)	C++17	100 / 100	1654 ms	65908 KiB

joioi

#include <bits/stdc++.h>
#define int long long
#define pii pair<int, int>
#define pb push_back
#define mk make_pair
#define F first
#define S second
#define ALL(x) x.begin(), x.end()

using namespace std;
using PQ = priority_queue<int, vector<int>, greater<int>>;
 
const int INF = 2e18;
const int maxn = 2e3 + 5;
const int M = 1e9 + 7;

int n, m, mx, mn;
int a[maxn][maxn];
int g[maxn][maxn];

void rotate () {
    // (3, 2) -> (2, 3)
    // (X, Y) -> (n - Y + 1, X)
    // (Y, X) -> (X, n - Y + 1)
    // (1, 4) -> (2, 3)
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= m; j++) {
            g[j][n - i + 1] = a[i][j];
        }
    }
    swap (n, m);
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= m; j++) {
            a[i][j] = g[i][j];
        }
    }
}

int check (int x) {
    int lim = m + 1;

    for (int i = 1; i <= n; i++) {
        int r = 0;
        for (int j = 1; j <= min (lim, m); j++) {
            if (mx - x <= a[i][j]) r = max (r, j);
            else break;
        }
        lim = r;
        for (int j = r + 1; j <= m; j++) {
            if (a[i][j] - x > mn) return 0; 
        }
    }
    return 1;
} 

int search () {
    int l = 0, r = 2e9 + 5;

    while (l < r) {
        int mid = (l + r) >> 1;

        if (check (mid)) r = mid;
        else l = mid + 1;
    }

    return r;
}

void init () {
    cin >> n >> m;

    mx = -INF, mn = INF;
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= m; j++) {
            cin >> a[i][j];
            mx = max (mx, a[i][j]);
            mn = min (mn, a[i][j]);
        }
    }
}

void solve () {
    int ans = INF;
    
    ans = min (ans, search ());
    rotate ();
    ans = min (ans, search ());
    rotate ();
    ans = min (ans, search ());
    rotate ();
    ans = min (ans, search ());

    cout << ans << "\n";
} 
 
signed main() {
    // ios::sync_with_stdio(0);
    // cin.tie(0);
    int t = 1;
    //cin >> t;
    while (t--) {
        init();
        solve();
    }
}

/*
4 4
1 12 6 11
11 10 2 14
10 1 9 20
4 17 19 10

*/

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