Submission #906807

#	Time	Username	Problem	Language	Result	Execution time	Memory
906807		Keshav211	Mecho (IOI09_mecho)	C++14	95 / 100	160 ms	17648 KiB

mecho

#include <algorithm>
#include <fstream>
#include <iostream>
#include <vector>
#include <map>
#include <stack>
#include <queue>
#include <set>
#include <chrono>
#include <string>
#include <numeric>
#include <cmath>
#include <iomanip>
#include <climits>
#include <bitset>
#define all(x) (x).begin(), (x).end()
#define vec(n) vll arr(n);
#define printarr(arr) for(auto i:arr)cout<<i<<" "; cout<<endl;
#define printdict(dict) for(auto i:dict)cout<<i.first<<": "<<i.second<<endl;
#define printadj(adj) for(ll i=0;i<n;i++){if(!adj[i].empty()){cout<<i<<": ";printarr(adj[i])}}
#define read(arr); for(ll i=0;i<arr.size();i++) cin>>arr[i];
#define readundirected(m) for(ll i=0;i<m;i++){ll a,b; cin>>a>>b; a--;b--; adj[a].pb(b);adj[b].pb(a);}
#define readdirected(m) for(ll i=0;i<m;i++){ll a,b; cin>>a>>b; a--;b--; adj[a].pb(b);}
#define readfunc(n) for(ll i=0;i<n;i++){ll a;cin>>a;a--;func_adj[i]=a;}
#define grid(n,m) for (ll i=1;i<=n;i++){for (ll j=1;j<=m;j++) cin>>graph[i][j];}
#define vll vector<ll>
#define sll set<ll>
#define msll multiset<ll>
#define qll queue<ll>
#define pll pair<ll,ll>
#define str string
#define pb push_back
#define ll long long
#define ld long double
using namespace std;
const str alph="abcdefghijklmnopqrstuvwxyz";
const str capalph="ABCDEFGHIJKLMNOPQRSTUVWXYZ";
const ll inf=2e5+1;
const ll graph_size=1000;
const ll mod=1e9+7;
const ll large=1e18;
const ll small=-1e18;
// Fast Input/Output
void fastio(){
    ios_base::sync_with_stdio(0);
    cin.tie(nullptr);
}
// File Input/Output
str fileio(const string&filePath=__FILE__){
    size_t lastSlash=filePath.find_last_of('/');
    size_t lastDot=filePath.rfind('.');
    return filePath.substr(lastSlash+1,lastDot-lastSlash-1);
}
// For Yes Or No Problems
str yes_or_no(bool test){
    if (test){
       return "YES";
    }
    return "NO";
}
ll n,m,q,s;
// Floodfill
char graph[graph_size+2][graph_size+2];
vector<pll> directions={{0,-1},{-1,0},{1,0},{0,1}};
bool floodfill_visited[graph_size+2][graph_size+2];
ll floodfill_bee_level[graph_size+2][graph_size+2];
vector<pll> hives;
void floodfill_bee_bfs(){
    for (ll i=0;i<=n+1;i++){
        for (ll j=0;j<=m+1;j++){
            floodfill_bee_level[i][j]=large;
            floodfill_visited[i][j]=0;
        }
    }
    queue<pll> q;
    for (auto i:hives){
        q.push(i);
        floodfill_bee_level[i.first][i.second]=0;
    }
    while (!q.empty()){
        pll curr=q.front();
        q.pop();
        ll x=curr.first;
        ll y=curr.second;
        floodfill_visited[x][y]=1;
        for (auto i:directions){
            if (graph[x+i.first][y+i.second]!='T' and x+i.first>=1 and x+i.first<=n and y+i.second>=1 and y+i.second<=m and floodfill_bee_level[x+i.first][y+i.second]==large){
                floodfill_bee_level[x+i.first][y+i.second]=floodfill_bee_level[x][y]+1;
                q.push({x+i.first,y+i.second});
            }
        }
    }
}
bool graph1[graph_size+2][graph_size+2];
ll floodfill_ans_level[graph_size+2][graph_size+2];
void floodfill_ans_bfs(pll coord,ll t){
    for (ll i=0;i<=n+1;i++){
        for (ll j=0;j<=m+1;j++){
            floodfill_ans_level[i][j]=large;
            floodfill_visited[i][j]=0;
        }
    }
    ll x=coord.first;
    ll y=coord.second;
    queue<pll> q;
    q.push({x,y});
    floodfill_ans_level[x][y]=0;
    while (!q.empty()){
        pll curr=q.front();
        q.pop();
        x=curr.first;
        y=curr.second;
        floodfill_visited[x][y]=1;
        for (auto i:directions){
            if (graph[x+i.first][y+i.second]!='T' and (floodfill_ans_level[x][y]+1)/s+t<floodfill_bee_level[x+i.first][y+i.second] and x+i.first>=1 and x+i.first<=n and y+i.second>=1 and y+i.second<=m and floodfill_ans_level[x+i.first][y+i.second]==large){
                floodfill_ans_level[x+i.first][y+i.second]=floodfill_ans_level[x][y]+1;
                q.push({x+i.first,y+i.second});
            }
        }
    }
}
// Binary Search
pll home,bear;
bool check(ll t){
    if (t>=floodfill_bee_level[bear.first][bear.second]){
        return 0;
    }
    floodfill_ans_bfs(bear,t);
    bool test=0;
    for (auto i:directions){
        test=max(test,floodfill_visited[home.first+i.first][home.second+i.second]);
    }
    return test;
}
// Returns the first value in the range such that check(value)=True.
ll first_true(ll low,ll high){
    while (low<high){
        ll mid=(low+high)/2;
        if (check(mid)){
            high=mid;
        }
        else{
            low=mid+1;
        }
    }
    return low;
}
// Returns the last value in the range such that check(value)=True.
ll last_true(ll low,ll high){
    while (low<high){
        ll mid=(low+high+1)/2;
        if (check(mid)){
            low=mid;
        }
        else{
            high=mid-1;
        }
    }
    return low;
}
int main(){
    // auto start_time=chrono::steady_clock::now();
    fastio();
    // str filename=fileio();
    // ifstream cin(filename+".in");
    // ofstream cout(filename+".out");
    ll t=1;
    // cin>>t;
    while (t--){
        cin>>n>>s;
        m=n;
        grid(n,m);
        for (ll i=1;i<=n;i++){
            for (ll j=1;j<=m;j++){
                if (graph[i][j]=='H'){
                    hives.pb({i,j});
                }
                if (graph[i][j]=='M'){
                    bear={i,j};
                }
                if (graph[i][j]=='D'){
                    home={i,j};
                }
            }
        }
        floodfill_bee_bfs();
        ll ans=last_true(0,large);
        if (!check(0)){
            ans--;
        }
        cout<<ans<<"\n";
    }
    // auto end_time=chrono::steady_clock::now();
    // auto elapsed_time=chrono::duration_cast<chrono::milliseconds>(end_time-start_time);
    // cout<<"Elapsed time: "<<elapsed_time.count()<<" milliseconds\n";
}

• Subtask 1: 95 / 100