Submission #715574

#	Time	Username	Problem	Language	Result	Execution time	Memory
715574		Iliya_	Tracks in the Snow (BOI13_tracks)	C++11	100 / 100	1116 ms	877104 KiB

tracks

// IN THE NAME OF GOD
#include<bits/stdc++.h>
#define endl '\n'
#define file_reading freopen("input.txt", "r", stdin); freopen("output.txt", "w", stdout);
#define flush cout.flush();
using namespace std;
typedef long long ll;
typedef long double dll;
typedef unsigned long long ull;
 
const int N = 4e3+5; 
int dat[N][N], mark[N][N], ans, having, must; 
vector<pair<int,int>> gone, later; 
int n,m;

void dfs(int x, int y){
	mark[x][y] = 1; 
	having++;
	if (x > 1 && dat[x][y] == dat[x-1][y] && !mark[x-1][y]) dfs(x-1,y);
	if (x < n && dat[x][y] == dat[x+1][y] && !mark[x+1][y]) dfs(x+1,y);
	if (y > 1 && dat[x][y] == dat[x][y-1] && !mark[x][y-1]) dfs(x,y-1);
	if (y < m && dat[x][y] == dat[x][y+1] && !mark[x][y+1]) dfs(x,y+1);
	if (x > 1 && dat[x][y] != dat[x-1][y] && !mark[x-1][y] && dat[x][y] + dat[x-1][y] == 3) later.push_back({x-1,y});
	if (x < n && dat[x][y] != dat[x+1][y] && !mark[x+1][y] && dat[x][y] + dat[x+1][y] == 3) later.push_back({x+1,y});
	if (y > 1 && dat[x][y] != dat[x][y-1] && !mark[x][y-1] && dat[x][y] + dat[x][y-1] == 3) later.push_back({x,y-1});
	if (y < m && dat[x][y] != dat[x][y+1] && !mark[x][y+1] && dat[x][y] + dat[x][y+1] == 3) later.push_back({x,y+1});
}
 
void solve(){  
	cin >> n >> m; 
	for(int i=1; i<=n; i++){
		for(int j=1; j<=m; j++){
			char g; cin >> g; 
			if (g == '.') dat[i][j] = 0; 
			else if (g == 'R') dat[i][j] = 1, must++; 
			else dat[i][j] = 2, must++; 
		}
	}
	if (must == 0){cout << 0 << endl; return;}
	ans = 1; 
	dfs(n,m); 
	while(having != must){
		ans++; 
		gone.clear(); 
		for(pair<int,int> cur : later) gone.push_back(cur); 
		later.clear();
		for(pair<int,int> cur : gone) if (!mark[cur.first][cur.second]) dfs(cur.first,cur.second); 
		
	}
	cout << ans << endl; 
}
 
int32_t main(){
	ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
	int t; t=1; //cin >> t;
	while(t--){solve();}
}

• Subtask 1: 30 / 30
• Subtask 2: 70 / 70