Submission #395117

#	Time	Username	Problem	Language	Result	Execution time	Memory
395117		MarcoMeijer	Mecho (IOI09_mecho)	C++14	100 / 100	624 ms	3000 KiB

mecho

#include <bits/stdc++.h>
using namespace std;
 
// macros
typedef long long ll;
typedef long double ld;
typedef pair<int, int> ii;
typedef pair<ll, ll> lll;
typedef tuple<int, int, int> iii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<iii> viii;
typedef vector<ll> vll;
typedef vector<lll> vlll;
#define REP(a,b,c) for(int a=int(b); a<int(c); a++)
#define RE(a,c) REP(a,0,c)
#define RE1(a,c) REP(a,1,c+1)
#define REI(a,b,c) REP(a,b,c+1)
#define REV(a,b,c) for(int a=int(c-1); a>=int(b); a--)
#define FOR(a,b) for(auto& a : b)
#define all(a) a.begin(), a.end()
#define INF 1e18
#define EPS 1e-9
#define pb push_back
#define popb pop_back
#define fi first
#define se second
 
// input
template<class T> void IN(T& x) {cin >> x;}
template<class H, class... T> void IN(H& h, T&... t) {IN(h); IN(t...); }
 
// output
template<class T1, class T2> void OUT(const pair<T1,T2>& x);
template<class T> void OUT(const vector<T>& x);
template<class T> void OUT(const T& x) {cout << x;}
template<class H, class... T> void OUT(const H& h, const T&... t) {OUT(h); OUT(t...); }
template<class T1, class T2> void OUT(const pair<T1,T2>& x) {OUT(x.fi,' ',x.se);}
template<class T> void OUT(const vector<T>& x) {RE(i,x.size()) OUT(i==0?"":" ",x[i]);}
template<class... T> void OUTL(const T&... t) {OUT(t..., "\n"); }
template<class H> void OUTLS(const H& h) {OUTL(h); }
template<class H, class... T> void OUTLS(const H& h, const T&... t) {OUT(h,' '); OUTLS(t...); }
 
// dp
template<class T> bool ckmin(T&a, T&b) { bool bl = a > b; a = min(a,b); return bl;}
template<class T> bool ckmax(T&a, T&b) { bool bl = a < b; a = max(a,b); return bl;}
 
void program();
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    program();
}
 
 
//===================//
//   begin program   //
//===================//
 
const int MX = 850;
const int N = (1<<20);

int n,s;
char ogr[MX][MX];
char gr[MX][MX];
int dx[]={-1,0,1,0};
int dy[]={0,1,0,-1};

queue<ii> bq, hq;

bool inside(int x, int y) {return x>=0 && x<n && y>=0 && y<n;}

bool moveHoney() {
    queue<ii> nq;
    while(!hq.empty()) {
        int x = hq.front().fi;
        int y = hq.front().se; hq.pop();
        if(gr[x][y] != 'M') continue;
        RE(d,4) {
            int nx = x+dx[d];
            int ny = y+dy[d];
            if(!inside(nx,ny)) continue;
            if(gr[nx][ny] == 'D') return true;
            if(gr[nx][ny] != 'G') continue;
            gr[nx][ny] = 'M';
            nq.push({nx,ny});
        }
    }
    hq = nq;
    return false;
}
void moveBees() {
    queue<ii> nq;
    while(!bq.empty()) {
        int x = bq.front().fi;
        int y = bq.front().se; bq.pop();
        RE(d,4) {
            int nx = x+dx[d];
            int ny = y+dy[d];
            if(!inside(nx,ny)) continue;
            if(gr[nx][ny] != 'G' && gr[nx][ny] != 'M') continue;
            gr[nx][ny] = 'H';
            nq.push({nx,ny});
        }
    }
    bq = nq;
}

bool possible(int x) {
    RE(i,n) RE(j,n) gr[i][j] = ogr[i][j];

    while(!bq.empty()) bq.pop();
    while(!hq.empty()) hq.pop();

    RE(i,n) RE(j,n) if(gr[i][j]=='H') bq.push({i,j});
    RE(i,n) RE(j,n) if(gr[i][j]=='M') hq.push({i,j});
    RE(_,x) moveBees();

    while(!hq.empty()) {
        RE(_,s) if(moveHoney()) return true;
        moveBees();
    }

    return false;
}

void program() {
    IN(n,s);
    RE(i,n) RE(j,n) IN(ogr[i][j]);

    if(!possible(0)) {
        OUTL(-1);
        return;
    }

    int lb=0, ub=n*n;
    while(lb != ub) {
        int mid=(lb+ub+1)/2;
        if(possible(mid)) lb=mid;
        else ub=mid-1;
    }
    OUTL(lb);
}

• Subtask 1: 100 / 100