hdu 1983 Kaitou Kid - The Phantom Thief (2) (DFS+BFS)

#include<iostream>#include<cstring>#include<cstdio>#include<queue>using namespace std;//44627062011-08-21 13:24:53Accepted1983406MS400K1727 BC++ashione#define N 10char map[N][N];int n,m,t,minstep,step[8]={0,1,0,-1,1,0,-1,0};bool use[N][N][2];//三维标记状态typedef struct p{int x,y,t,f;int pathx[N*N],pathy[N*N]; //pathx,y 表示的是通路路径（如果可以到达的话）}p;p s;void init(){ //s表示为初始点。cin>>n>>m>>t;minstep=N;memset(map,'#',sizeof(map));for(int i=1;i<=n;i++){for(int j=1;j<=m;j++){cin>>map[i][j];if(map[i][j]=='S')s.x=i,s.y=j,s.t=0,s.f=0;}}}void bfs(int k){if( k > 4 || k>minstep) //BFS 搜索 不可能大于四个围点，也不能大于当年最大值return ;queue<p> q;q.push(s);memset(use,false,sizeof(use));bool succeed=false;use[s.x][s.y][s.f]=true;p temp,now;while(!q.empty()){ temp=q.front();q.pop();if(map[temp.x][temp.y] == 'E' && temp.f ){ //若已经搜到，并且拿到宝石。succeed = true;break;}for(int i=0;i<8;i+=2){now=temp;now.x+=step[i];now.y+=step[i+1];if(map[now.x][now.y] =='J')now.f=1;if(map[now.x][now.y] =='#' ||now.t>=t || use[now.x][now.y][now.f])continue;use[now.x][now.y][now.f]=true;now.t++;now.pathx[now.t]=now.x;now.pathy[now.t]=now.y;q.push(now);}}if(!succeed){//不成功，即为满足题意。minstep = minstep < k?minstep:k;return ;}for(int j=1;j<=temp.t ;j++){//沿着通路判断，int x=temp.pathx[j],y=temp.pathy[j];char tc=map[x][y];if(tc == 'E' || tc == 'S')//DFS回溯判断是否通路continue;map[x][y]='#';bfs(k+1);map[x][y]=tc;}}int main(){int T;cin>>T;while(T--){init();bfs(0);cout<<minstep<<endl;}return 0;}