Submission #150891

#	Time	Username	Problem	Language	Result	Execution time	Memory
150891		cheetose	Portals (BOI14_portals)	C++11	100 / 100	686 ms	124916 KiB

portals

#include<cstdio>
#include<cstdlib>
#include<iostream>
#include<vector>
#include<queue>
#include<bitset>
#include<string>
#include<stack>
#include<set>
#include<unordered_set>
#include<map>
#include<unordered_map>
#include<cstring>
#include<complex>
#include<cmath>
#include<iomanip>
#include<numeric>
#include<algorithm>
#include<list>
#include<functional>
#include<cassert>
#define mp make_pair
#define pb push_back
#define X first
#define Y second
#define y0 y12
#define y1 y22
#define INF 987654321
#define PI 3.141592653589793238462643383279502884
#define fup(i,a,b,c) for(int (i)=(a);(i)<=(b);(i)+=(c))
#define fdn(i,a,b,c) for(int (i)=(a);(i)>=(b);(i)-=(c))
#define MEM0(a) memset((a),0,sizeof(a));
#define MEM_1(a) memset((a),-1,sizeof(a));
#define ALL(a) a.begin(),a.end()
#define SYNC ios_base::sync_with_stdio(false);cin.tie(0)
using namespace std;
typedef long long ll;
typedef long double ld;
typedef double db;
typedef unsigned int uint;
typedef unsigned long long ull;
typedef pair<int, int> Pi;
typedef pair<ll, ll> Pll;
typedef pair<ld, ld> Pd;
typedef vector<int> Vi;
typedef vector<ll> Vll;
typedef vector<double> Vd;
typedef vector<Pi> VPi;
typedef vector<Pll> VPll;
typedef vector<Pd> VPd;
typedef tuple<int, int, int> iii;
typedef tuple<int,int,int,int> iiii;
typedef tuple<ll, ll, ll> LLL;
typedef vector<iii> Viii;
typedef vector<LLL> VLLL;
typedef complex<double> base;
const ll MOD = 1000000007;
ll POW(ll a, ll b, ll MMM = MOD) {ll ret=1; for(;b;b>>=1,a=(a*a)%MMM)if(b&1)ret=(ret*a)% MMM; return ret; }
ll gcd(ll a, ll b) { return b ? gcd(b, a%b) : a; }
ll lcm(ll a, ll b) { if (a == 0 || b == 0)return a + b; return a*(b / gcd(a, b)); }
int dx[] = { 0,1,0,-1,1,1,-1,-1 }, dy[] = { 1,0,-1,0,1,-1,1,-1 };

char s[1000][1001];
int U[1000][1000],D[1000][1000],L[1000][1000],R[1000][1000];
VPi v[1000000];
int dist[1000000];
bool chk[1000000];
int n,m;
inline int Z(int x,int y){return x*m+y;}
int main() {
	fill(dist,dist+1000000,INF);
	scanf("%d%d",&n,&m);
	fup(i,0,n-1,1)scanf("%s",s[i]);
	int S,E;
	fup(i,0,n-1,1)
		fup(j,0,m-1,1)
	{
		if(s[i][j]=='S')S=Z(i,j);
		if(s[i][j]=='C')E=Z(i,j);
	}
	fup(i,0,n-1,1)
	{
		int p=-1;
		fup(j,0,m-1,1)
		{
			if(s[i][j]=='#')p=j;
			else L[i][j]=p;
		}
		p=m;
		fdn(j,m-1,0,1)
		{
			if(s[i][j]=='#')p=j;
			else R[i][j]=p;
		}
	}
	fup(j,0,m-1,1)
	{
		int p=-1;
		fup(i,0,n-1,1)
		{
			if(s[i][j]=='#')p=i;
			else U[i][j]=p;
		}
		p=n;
		fdn(i,n-1,0,1)
		{
			if(s[i][j]=='#')p=i;
			else D[i][j]=p;
		}
	}
	fup(x,0,n-1,1)
		fup(y,0,m-1,1)
	{
		if(s[x][y]=='#')continue;
		int now=Z(x,y);
		fup(i,0,3,1)
		{
			int nx=x+dx[i],ny=y+dy[i];
			if(nx>=0 && nx<n && ny>=0 && ny<m && s[nx][ny]!='#')
				v[now].pb(mp(Z(nx,ny),1));
		}
		int mm=min({abs(x-U[x][y]),abs(x-D[x][y]),abs(y-L[x][y]),abs(y-R[x][y])});
		int next=Z(U[x][y]+1,y);
		v[now].pb(mp(next,mm));
		next=Z(D[x][y]-1,y);
		v[now].pb(mp(next,mm));
		next=Z(x,L[x][y]+1);
		v[now].pb(mp(next,mm));
		next=Z(x,R[x][y]-1);
		v[now].pb(mp(next,mm));
	}
	priority_queue<Pi> q;
	dist[S] = 0;
	q.push({ 0,S });
	while (!q.empty())
	{
		int x = q.top().Y;
		q.pop();
		if (chk[x])continue;
		chk[x] = 1;
		for (const auto& p : v[x])
		{
			int next = p.X, cost = p.Y;
			if (dist[next] > dist[x]+cost)
			{
				dist[next] = dist[x] + cost;
				q.push({ -dist[next],next });
			}
		}
	}
	printf("%d",dist[E]);
}

Compilation message (stderr)

portals.cpp: In function 'int main()':
portals.cpp:72:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d",&n,&m);
  ~~~~~^~~~~~~~~~~~~~
portals.cpp:73:21: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  fup(i,0,n-1,1)scanf("%s",s[i]);
                ~~~~~^~~~~~~~~~~
portals.cpp:151:8: warning: 'E' may be used uninitialized in this function [-Wmaybe-uninitialized]
  printf("%d",dist[E]);
  ~~~~~~^~~~~~~~~~~~~~

• Subtask 1: 11 / 11
• Subtask 2: 20 / 20
• Subtask 3: 20 / 20
• Subtask 4: 19 / 19
• Subtask 5: 30 / 30