Submission #476426

#	Time	Username	Problem	Language	Result	Execution time	Memory
476426		Morley	Mecho (IOI09_mecho)	C++14	18 / 100	383 ms	65544 KiB

mecho

#include <bits/stdc++.h>
using namespace std;

using ll = long long;
using vi = vector<int>;
using vl = vector<long long>;
using vb = vector<bool>;
using vvi = vector<vector<int>>;
using vvpi = vector<vector<pair<int,int>>>;
using vvb = vector<vector<bool>>;
using str = string;
using pi= pair<int,int>;
using pll = pair<ll,ll>;
using vpi = vector<pi>;
using ti = tuple<int,int,int>;
using vti = vector<ti>;

#define pb push_back
#define rs resize
#define mp make_pair
#define FOR(x,y,z) for(int x=y; x<z; x++)
#define F0R(x,z) for(int x=0; x<z; x++)
#define all(a) a.begin() , a.end()

ll mx = 1000000000000000000;
int inf = 2000000000;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);

	int n,s; cin >> n >> s;
	vector<str> F(n);
	for(int i=0;i<n;i++) cin >> F[i];
	vvi hd(n,vi(n,inf));
	queue<ti> Q;
	for(int i=0;i<n;i++) for(int j=0;j<n;j++) if(F[i][j]=='H') Q.push({i,j,0});
	while(!Q.empty()) {
		ti cur=Q.front(); Q.pop();
		int i=get<0>(cur),j=get<1>(cur),d=get<2>(cur);
		//cout << i << j << d << "\n";
		if(d>=hd[i][j]) continue;
		hd[i][j]=d;
		if(i>0 && hd[i-1][j]==inf && (F[i-1][j]=='G' || F[i-1][j]=='M')) Q.push({i-1,j,d+1});
		if(i<n-1 && hd[i+1][j]==inf && (F[i+1][j]=='G' || F[i+1][j]=='M')) Q.push({i+1,j,d+1});
		if(j>0 && hd[i][j-1]==inf && (F[i][j-1]=='G' || F[i][j-1]=='M')) Q.push({i,j-1,d+1});
		if(j<n-1 && hd[i][j+1]==inf && (F[i][j+1]=='G' || F[i][j+1]=='M')) Q.push({i,j+1,d+1});
	}
	//for(int i=0;i<n;i++) {for(int j=0;j<n;j++) if(hd[i][j]<inf) cout << hd[i][j]; else cout << "T"; cout << "\n";}
	int lob=0,upb=2*n;
	while(lob<upb) {
		int tst=(lob+upb+1)/2;
		queue<ti> Qp;
		for(int i=0;i<n;i++) for(int j=0;j<n;j++) if(F[i][j]=='M') Qp.push({i,j,0});
		bool good=false; vvb vis(n,vb(n,false));
		while(!Qp.empty()) {
			ti cur=Qp.front(); Qp.pop();
			int i=get<0>(cur),j=get<1>(cur),d=get<2>(cur);
			//cout << i << j << d << " ";
			vis[i][j]=true;
			if(F[i][j]=='D') {good=true; break;}
			if(tst+d/s>=hd[i][j]) continue;
			if(i>0 && !vis[i-1][j] && (F[i-1][j]=='G' || F[i-1][j]=='D')) Qp.push({i-1,j,d+1});
			if(i<n-1 && !vis[i+1][j] && (F[i+1][j]=='G' || F[i+1][j]=='D')) Qp.push({i+1,j,d+1});
			if(j>0 && !vis[i][j-1] && (F[i][j-1]=='G' || F[i][j-1]=='D')) Qp.push({i,j-1,d+1});
			if(j<n-1 && !vis[i][j+1] && (F[i][j+1]=='G' || F[i][j+1]=='D')) Qp.push({i,j+1,d+1});
		}
		if(!good) upb=tst-1;
		else lob=tst;
	}
	cout << upb;

	return 0;
}

• Subtask 1: 18 / 100