Submission #885966

#	Time	Username	Problem	Language	Result	Execution time	Memory
885966		JakobZorz	Mecho (IOI09_mecho)	C++17	72 / 100	1084 ms	3420 KiB

mecho

#include<iostream>
#include<vector>
#include<queue>
#include<stack>
#include<algorithm>
#include<limits.h>
#include<math.h>
#include<map>
#include<set>
#include<unordered_map>
#include<unordered_set>
#include<iomanip>
#include<cstring>
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
using namespace std;
//const int MOD=1e9+7;
//typedef pair<ll,ll>Point;
//typedef pair<ll,ll>Line;
//#define x first
//#define y second

int n,s;
vector<string>m;
vector<string>cm;
queue<pair<int,int>>q1,q2;

vector<pair<int,int>>get_nbs(pair<int,int>pos){
    vector<pair<int,int>>res;
    if(pos.first!=0)
        res.emplace_back(pos.first-1,pos.second);
    if(pos.second!=0)
        res.emplace_back(pos.first,pos.second-1);
    if(pos.first!=n-1)
        res.emplace_back(pos.first+1,pos.second);
    if(pos.second!=n-1)
        res.emplace_back(pos.first,pos.second+1);
    return res;
}

void spread_bees(){
    queue<pair<int,int>>q;
    while(q2.size()){
        pair<int,int>curr=q2.front();
        q2.pop();
        vector<pair<int,int>>nbs=get_nbs(curr);
        for(pair<int,int>i:nbs){
            if(cm[i.first][i.second]=='H')
                continue;
            if(cm[i.first][i.second]=='T')
                continue;
            if(cm[i.first][i.second]=='D')
                continue;
            cm[i.first][i.second]='H';
            q.push(i);
        }
    }
    q2=q;
}

bool check(int waits){
    cm=m;
    q1=queue<pair<int,int>>();
    q2=queue<pair<int,int>>();
    
    for(int x=0;x<n;x++)
        for(int y=0;y<n;y++){
            if(cm[x][y]=='H')
                q2.push({x,y});
            
            if(cm[x][y]=='M')
                q1.push({x,y});
        }
    
    while(waits--){
        spread_bees();
    }
    
    while(q1.size()||q2.size()){
        for(int i=0;i<s;i++){
            queue<pair<int,int>>q;
            while(q1.size()){
                pair<int,int>curr=q1.front();
                q1.pop();
                if(cm[curr.first][curr.second]!='M')
                    continue;
                vector<pair<int,int>>nbs=get_nbs(curr);
                for(pair<int,int>i:nbs){
                    if(cm[i.first][i.second]=='H')
                        continue;
                    if(cm[i.first][i.second]=='T')
                        continue;
                    if(cm[i.first][i.second]=='D')
                        return true;
                    if(cm[i.first][i.second]=='M')
                        continue;
                    cm[i.first][i.second]='M';
                    q.push(i);
                }
            }
            q1=q;
        }
        
        spread_bees();
    }
    
    return false;
}

void solve(){
    cin>>n>>s;
    m.resize(n);
    for(string&i:m)
        cin>>i;
    
    int l=0,r=2e5;
    while(l<r-1){
        int m=(l+r)/2;
        if(check(m))
            l=m;
        else
            r=m;
    }
    cout<<l<<"\n";
}

int main(){
    ios::sync_with_stdio(false);cout.tie(NULL);cin.tie(NULL);
    //freopen("bank.in","r",stdin);freopen("bank.out","w",stdout);
    int t=1;//cin>>t;
    while(t--)solve();
    return 0;
}

/*
 
7 3
TTTTTTT
TGGGGGT
TGGGGGT
MGGGGGD
TGGGGGT
TGGGGGT
THHHHHT
 
 
7 3
TTTTTTT
TGGGGGT
TGGGGGT
MGGGGGD
TGGGGGT
TGGGGGT
TGHHGGT
 
 */

• Subtask 1: 72 / 100