HDU1242 Rescue 简单bfs
求最小步数
1 #include<iostream> 2 #include<cstdio> 3 #include<cstring> 4 #include<cstdlib> 5 #include<queue> 6 using namespace std; 7 char map[211][211]; 8 struct node 9 { 10 int x,y,step; 11 friend bool operator<(node a,node b) 12 { 13 return a.step>b.step; 14 } 15 }cur,next; 16 int ex,ey,sx,sy; 17 int n,m; 18 19 int bfs(void) 20 { 21 priority_queue<node>q; 22 cur.x=sx; 23 cur.y=sy; 24 cur.step=0; 25 q.push(cur); 26 while(!q.empty()) 27 { 28 cur=q.top(); 29 q.pop(); 30 if(cur.x==ex&&cur.y==ey) return 1; 31 if(cur.x-1>=0&&map[cur.x-1][cur.y]!='#') 32 { 33 next=cur; 34 next.x--; 35 next.step++; 36 if(map[next.x][next.y]=='x') next.step++; 37 q.push(next); 38 map[next.x][next.y]='#'; 39 } 40 if(cur.y-1>=0&&map[cur.x][cur.y-1]!='#') 41 { 42 next=cur; 43 next.y--; 44 next.step++; 45 if(map[next.x][next.y]=='x') next.step++; 46 q.push(next); 47 map[next.x][next.y]='#'; 48 } 49 if(cur.x+1<n&&map[cur.x+1][cur.y]!='#') 50 { 51 next=cur; 52 next.x++; 53 next.step++; 54 if(map[next.x][next.y]=='x') next.step++; 55 q.push(next); 56 map[next.x][next.y]='#'; 57 } 58 if(cur.y+1<m&&map[cur.x][cur.y+1]!='#') 59 { 60 next=cur; 61 next.y++; 62 next.step++; 63 if(map[next.x][next.y]=='x') next.step++; 64 q.push(next); 65 map[next.x][next.y]='#'; 66 } 67 } 68 return 0; 69 } 70 int main() 71 { 72 while(scanf("%d %d",&n,&m)!=EOF) 73 { 74 for(int i=0;i<n;i++) 75 { 76 scanf("%s",&map[i]); 77 for(int j=0;j<m;j++) 78 { 79 if(map[i][j]=='r') 80 { 81 sx=i; 82 sy=j; 83 } 84 if(map[i][j]=='a') 85 { 86 ex=i; 87 ey=j; 88 } 89 } 90 } 91 if(bfs()) printf("%d\n",cur.step); 92 else printf("Poor ANGEL has to stay in the prison all his life.\n"); 93 } 94 }
