【网络流24题】孤岛营救问题

这道题和网络流有什么关系吗?
状态压缩BFS

/*
@Date    : 2019-07-16 21:37:18
@Author  : Adscn (adscn@qq.com)
@Link    : https://www.cnblogs.com/LLCSBlog
*/
#include<bits/stdc++.h>
using namespace std;
#define IL inline
#define RG register
#define gi getint()
#define gc getchar()
#define File(a) freopen(a".in","r",stdin);freopen(a".out","w",stdout)
IL int getint()
{
	RG int xi=0;
	RG char ch=gc;
	bool f=0;
	while(ch<'0'|ch>'9')ch=='-'?f=1:f,ch=gc;
	while(ch>='0'&ch<='9')xi=(xi<<1)+(xi<<3)+ch-48,ch=gc;
	return f?-xi:xi;
}
template<typename T>
IL void pi(T k,char ch=0)
{
	if(k<0)k=-k,putchar('-');
	if(k>=10)pi(k/10,0);
	putchar(k%10+'0');
	if(ch)putchar(ch);
}
int tab[12][12][12][12];
vector<int> key[12][12];
bool vis[12][12][(1<<15)];
int dx[]={0,-1,1,0};
int dy[]={1,0,0,-1};
struct node{int nx,ny,nk,ans;};
inline void getkey(int &k,int x,int y)
{
	for(auto &&p:key[x][y])k|=(1<<p);
}
int main(void)
{
	#ifndef ONLINE_JUDGE
//	File("");
	#endif
	int n=gi,m=gi,p=gi;
	int k=gi;
	for(int i=1;i<=k;++i)
	{
		int _x=gi,_y=gi,x2=gi,y2=gi,G=gi;
		tab[_x][_y][x2][y2]=tab[x2][y2][_x][_y]=(G!=0?G:p+1);
	}
	int s=gi;
	for(int i=1;i<=s;++i)
	{
		int a=gi,b=gi,c=gi;
		key[a][b].push_back(c);
	}
	static std::queue<node>Q;
	int TMP=1;
	getkey(TMP,1,1);
	Q.push({1,1,TMP,0});
	vis[1][1][TMP]=1;
	while(!Q.empty())
	{
		node p=Q.front();Q.pop();
		if(p.nx==n&&p.ny==m)pi(p.ans),exit(0);
		for(int i=0;i<4;++i)
		{
			int nx=p.nx+dx[i],ny=p.ny+dy[i],nk=p.nk,state=tab[p.nx][p.ny][nx][ny];
			getkey(nk,nx,ny);
			if(nx<1||nx>n||ny<1||ny>m||(p.nk&(1<<state))==0||vis[nx][ny][nk])continue;	
			Q.push((node){nx,ny,nk,p.ans+1}),vis[nx][ny][nk]=1;
		}
	}
	pi(-1);
	return 0;
}
原文地址:https://www.cnblogs.com/LLCSBlog/p/11199240.html