oj.uz

Submission #1114040

# Submission time Handle Problem Language Result Execution time Memory
1114040 2024-11-18T06:48:02 Z Dan4Life The Kingdom of JOIOI (JOI17_joioi) C++17
0 / 100
 21 ms 36176 KB 
#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define sz(a) (int)a.size()
#define all(a) begin(a),end(a)
const int N = (int)2e3+10;
int n, m, lst[N];
int dp[N][N], pref[N][N];
int a[N][N], b[N][N], c[N][N];

void Rotate(){
	for(int i = 0; i < n; i++)
		for(int j = 0; j < m; j++)
			swap(b[i][j],b[j][i]);
	swap(n,m);
	for(int i = 0; i < n; i++)
		reverse(b[i],b[i]+m);
}

bool calc(){
	for(int k : {0,1}){
		memset(dp,0,sizeof(dp));
		memset(lst,0,sizeof(lst));
		for(int i = 0; i < n; i++){
			for(int j = 0; j < m; j++){
				pref[i][j+1] = pref[i][j]+(!b[i][j] or b[i][j]==k);
				if(b[i][j]==k) lst[i]=j+1;
			}
		}
		int bst=-1, bst2;
		for(int i = 0; i < n; i++){
			bst2=-1;
			for(int j = 0; j <= m; j++){
				if(pref[i][j]!=j) break;
				if(!i) dp[i][j]=(j!=m and j>=lst[i]);
				else if(bst!=-1) dp[i][j]=(bst<=j and j>=lst[i]);
				if(dp[i][j] and bst2==-1) bst2=j;
			}
			bst=bst2;
		}
		bool ok = 0;
		for(int i = 1; i <= m; i++) ok|=dp[n-1][i];
		if(ok) return 1;
	}
	return 0;
}

int mn = (int)1e9, mx = 0;
bool chk(int R){
	memset(b,0,sizeof(b));
	for(int i = 0; i < n; i++){
		for(int j = 0; j < m; j++){
			if(a[i][j]>mn+R) b[i][j]=2;
			if(a[i][j]<mx-R){
				if(b[i][j]==2) return 0;
				b[i][j] = 1;
			}
		}
	}
	bool ok = 0;
	for(int i = 0; i < 4; i++) 
		ok|=calc(), Rotate();
	return ok;
}

int main(){
	ios_base::sync_with_stdio(false); cin.tie(0);
	cin >> n >> m;
	for(int i = 0; i < n; i++)
		for(int j = 0; j < m; j++)
			cin >> a[i][j],mn=min(mn,a[i][j]),mx=max(mx,a[i][j]);
	int l = 0, r = mx-mn;
	while(l<r){
		int mid = (l+r)/2;
		if(chk(mid)) r=mid;
		else l=mid+1;
	}
	cout << l << "\n";
}

Subtask #1
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 20 ms 36176 KB Output is correct
2 Incorrect 21 ms 36176 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #2
0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 20 ms 36176 KB Output is correct
2 Incorrect 21 ms 36176 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #3
0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 20 ms 36176 KB Output is correct
2 Incorrect 21 ms 36176 KB Output isn't correct
3 Halted 0 ms 0 KB -