Submission #415037

#	Time	Username	Problem	Language	Result	Execution time	Memory
415037		nvmdava	The Kingdom of JOIOI (JOI17_joioi)	C++17	100 / 100	757 ms	54920 KiB

joioi

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ff first
#define ss second
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int N = 100005;
const ll MOD = 1000000007;
const ll INF = 0x3f3f3f3f3f3f3f3f;
const int SQ = 300;

int n, m;
int mn = 1'000'000'000, mx = 0;

int a[2005][2005];

void flipx(){
    for(int i = 1; i <= n; ++i)
        for(int j = 1; j <= m / 2; ++j)
            swap(a[i][j], a[i][m + 1 - j]);
}
void flipy(){
    for(int i = 1; i <= n / 2; ++i)
        for(int j = 1; j <= m; ++j)
            swap(a[i][j], a[n + 1 - i][j]);
}

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

int solve(){
    int l = 0, r = 1'000'000'000;
    while(l != r){
        int m = (l + r) >> 1;
        if(check(m))
            r = m;
        else
            l = m + 1;
    }
    return l;
}

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

    cin>>n>>m;

    for(int i = 1; i <= n; ++i){
        for(int j = 1; j <= m; ++j){
            cin>>a[i][j];
            mn = min(mn, a[i][j]);
            mx = max(mx, a[i][j]);
        }
    }
    int res = 1'000'000'000;
    res = min(res, solve());
    flipx();
    res = min(res, solve());
    flipy();
    res = min(res, solve());
    flipx();
    res = min(res, solve());
    cout<<res;
}

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