Submission #464388

#	Time	Username	Problem	Language	Result	Execution time	Memory
464388		amunduzbaev	T-Covering (eJOI19_covering)	C++14	30 / 100	576 ms	16044 KiB

covering

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

#define int long long

void solve(){
	int n, m; cin>>n>>m;
	vector<vector<int>> a(n, vector<int>(m));
	vector<vector<int>> is(n, vector<int>(m));
	for(int i=0;i<n;i++){
		for(int j=0;j<m;j++){
			cin>>a[i][j];
		}
	} 
	int k; cin>>k;
	vector<array<int, 2>> cc(k);
	for(int i=0;i<k;i++) cin>>cc[i][0]>>cc[i][1];
	if(k <= 10){
		int ch[4][3][2] = {
			{
				{0, 1}, 
				{0, -1}, 
				{1, 0}
			},
			{
				{0, 1}, 
				{0, -1}, 
				{-1, 0}
			},
			{
				{0, 1}, 
				{-1, 0}, 
				{1, 0}
			},
			{
				{0, -1}, 
				{-1, 0}, 
				{1, 0}
			}
		};

		auto check = [&](int i, int j) -> bool{
			return (~i && i < n && ~j && j < m);
		}; 
		vector<vector<vector<array<int, 2>>>> neib(4, vector<vector<array<int, 2>>>(k));
		vector<vector<bool>> isok(4, vector<bool>(k));
		for(int i=0;i<k;i++){
			for(int t=0;t<4;t++){
				isok[t][i] = 1;
				for(int j=0;j<3;j++){
					int x = cc[i][0] + ch[t][j][0], y = cc[i][1] + ch[t][j][1];
					isok[t][i] = isok[t][i] & check(x, y);
					neib[t][i].push_back({x, y});
				} neib[t][i].push_back({cc[i][0], cc[i][1]});
			}
		}

	 
		int res = -1;
		for(int mask=0;mask<(1<<(k*2));mask++){
			int sum = 0, tt = 0;
			bool ok = 1;
			for(int i=0;i<k;i++){
				int t = (2 * (mask>>tt&1) + (mask>>(tt+1)&1)); tt += 2;
				if(!isok[t][i]) { ok = 0; break; }
				for(auto x : neib[t][i]){
					if(is[x[0]][x[1]]) { ok = 0; break; }
					is[x[0]][x[1]] = 1;
					sum += a[x[0]][x[1]];
				} if(!ok) break;
			}
			
			if(ok) res = max(res, sum);
			tt = 0;
			for(int i=0;i<k;i++){
				int t = (2 * (mask>>tt&1) + (mask>>(tt+1)&1)); tt += 2;
				for(auto x : neib[t][i]){
					is[x[0]][x[1]] = 0;
				}
			}
		}
		
		if(res > -1) cout<<res<<"\n";
		else cout<<"No\n";
	} else {
		int ch[4][2] = {{0, 1}, {0, -1}, {1, 0}, {-1, 0}};
		for(int i=0;i<k;i++){
			is[cc[i][0]][cc[i][1]] = 1;
		}
		int res = 0;
		auto check = [&](int i, int j) -> bool{
			return (~i && i < n && ~j && j < m);
		}; 
	 
		for(int t=0;t<k;t++){
			int i = cc[t][0], j = cc[t][1], cnt = 0;
			int sum = a[i][j], mn = 1e3;
			for(int t=0;t<4;t++){
				int x = i + ch[t][0], y = j + ch[t][1];
				if(!check(x, y)) cnt++;
				else if(is[x][y]) cnt++;
				else sum += a[x][y], mn = min(mn, a[x][y]);
			} if(cnt > 1) {
				cout<<"No\n";
				return;
			} if(cnt == 1){
				res = res + sum;
			} else {
				res = res + sum - mn;
			}
		}
		cout<<res<<"\n";
	}
}

signed main(){
	ios_base::sync_with_stdio(0); cin.tie(0);
	int t = 1;
	//~ cin>>t;
	while(t--) solve();
}

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 0 / 10
• Subtask 4: 0 / 10
• Subtask 5: 15 / 15
• Subtask 6: 0 / 20
• Subtask 7: 0 / 30