Submission #750389

#	Time	Username	Problem	Language	Result	Execution time	Memory
750389		pcc	The Kingdom of JOIOI (JOI17_joioi)	C++14	100 / 100	1060 ms	51920 KiB

joioi

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

const int mxn = 2022;
int arr[mxn][mxn],lim[mxn];
int n,m;
int small = 1e9+10;

bool calc(int d){
	for(lim[1] = 1;lim[1]<=m&&arr[1][lim[1]]<=small+d;lim[1]++);
	for(int i = 2;i<=n;i++){
		for(lim[i] = 1;lim[i]<lim[i-1]&&arr[i][lim[i]]<=small+d;lim[i]++);
	}
	int big = 0,small = 1e9+10;
	for(int i = 1;i<=n;i++){
		for(int j = m;j>=lim[i];j--)big = max(big,arr[i][j]),small = min(small,arr[i][j]);
	}
	return big-small<=d;
}

bool f(int d){
	bool flag = false;
	flag = calc(d);
	for(int i = 1;i<=n;i++)reverse(arr[i]+1,arr[i]+1+m);
	flag = flag||calc(d);
	reverse(arr+1,arr+n+1);
	flag = flag||calc(d);
	for(int i = 1;i<=n;i++)reverse(arr[i]+1,arr[i]+1+m);
	flag = flag||calc(d);
	return flag;
}

int main(){
	ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
	cin>>n>>m;
	int big = 0;
	for(int i = 1;i<=n;i++)
		for(int j = 1;j<=m;j++)cin>>arr[i][j],big = max(big,arr[i][j]),small = min(small,arr[i][j]);
	int l = 0,r = big;
	while(l != r){
		int mid = (l+r)>>1;
		if(f(mid))r = mid;
		else l = mid+1;
	}
	cout<<l;
}

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