Submission #989666

#	Time	Username	Problem	Language	Result	Execution time	Memory
989666		aaaaaarroz	Mecho (IOI09_mecho)	C++17	100 / 100	192 ms	6336 KiB

mecho

#include <bits/stdc++.h>
using namespace std;
pair<int,int>inicio;
pair<int,int>final;
bool limites(int x, int y, int n){
	if(x>=0&&x<n&&y>=0&&y<n){
		return true;
	}
	else{
		return false;
	}
}
bool bfs(vector<vector<char>>&grid,vector<vector<int>>&bee, int &s, int n, int time){
	vector<int>dx={1,0,-1,0};
	vector<int>dy={0,1,0,-1};
	vector<vector<int>>dist(n,vector<int>(n,-1));
	dist[inicio.first][inicio.second]=0;
	if((dist[inicio.first][inicio.second]+time)>bee[inicio.first][inicio.second]){
		return false;
	}
	queue<pair<int,int>>cola;
	cola.push({inicio});
	while(!cola.empty()){
		int x=cola.front().first;
		int y=cola.front().second;
		cola.pop();
		for(int i=0;i<4;i++){
			int xx=x+dx[i];
			int yy=y+dy[i];
			if(limites(xx,yy,n)&&dist[xx][yy]==-1&&((floor((dist[x][y]+1)/s)+time)<=bee[xx][yy])&&grid[xx][yy]!='T'){
				dist[xx][yy]=dist[x][y]+1;
				cola.push({xx,yy});
			}
		}
	}
	if(dist[final.first][final.second]==-1){
		return false;
	}
	else{
		return true;
	}
}
int main() {
	int n,s;
	cin>>n>>s;
	vector<vector<char>>grid(n,vector<char>(n));
	vector<pair<int,int>>abejas;
	for(int i=0;i<n;i++){
		for(int j=0;j<n;j++){
			cin>>grid[i][j];
			if(grid[i][j]=='H'){
				abejas.push_back({i,j});
			}
			else if(grid[i][j]=='M'){
				inicio={i,j};
			}
			else if(grid[i][j]=='D'){
				final={i,j};
			}
		}
	}
	vector<vector<int>>bee(n,vector<int>(n,INT_MAX));
	queue<pair<int,int>>cola;
	for(int i=0;i<abejas.size();i++){
		cola.push(abejas[i]);
		bee[abejas[i].first][abejas[i].second]=0;
	}
	vector<int>dx={1,0,-1,0};
	vector<int>dy={0,1,0,-1};
	while(!cola.empty()){
		int x=cola.front().first;
		int y=cola.front().second;
		cola.pop();
		for(int i=0;i<4;i++){
			int xx=x+dx[i];
			int yy=y+dy[i];
			if(limites(xx,yy,n)&&bee[xx][yy]==INT_MAX&&grid[xx][yy]!='T'&&grid[xx][yy]!='D'){
				bee[xx][yy]=bee[x][y]+1;
				cola.push({xx,yy});
			}
		}
	}
	if(!bfs(grid,bee,s,n,0)){
		cout<<"-1\n";
		return 0;
	}
	int l=0, r=1000000;
	while(l<r){
		int mid=(l+r+1)/2;
		if(bfs(grid,bee,s,n,mid)){
			l=mid;
		}
		else{
			r=mid-1;
		}
	}
	cout<<r-1<<"\n";
}

Compilation message (stderr)

mecho.cpp: In function 'int main()':
mecho.cpp:64:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   64 |  for(int i=0;i<abejas.size();i++){
      |              ~^~~~~~~~~~~~~~

• Subtask 1: 100 / 100