88 lines
2.0 KiB
C++
88 lines
2.0 KiB
C++
//BFS算法入门
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//https://blog.csdn.net/qq_42757965/article/details/82019460
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//好文！！！！
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#include<stdio.h>
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#include<string.h>
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#include<queue>
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using namespace std;
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const int maxn=205;
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char ch[maxn][maxn];
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int dis[maxn][maxn];//做为标记如果这个点搜索过了标记为1,没有搜索过标记为0；
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int d[4][2]={1,0,-1,0,0,1,0,-1};//能走的四个方向；
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int n,m;
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int edx,edy,enx,eny;
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struct stu
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{
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int x;
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int y;
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int step;
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}A,B;
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void bfs(int x,int y)
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{
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queue<stu> que;
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A.x=x;
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A.y=y;
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A.step=0;
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dis[x][y]=1;
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que.push(A);
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int cnt=-1;
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while(!que.empty())
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{
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A=que.front();//把队列的顶端元素取出，
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que.pop();
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if(A.x==enx&&A.y==eny)//如果找到了终点那么搜索就结束了。
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{
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cnt=A.step;
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break;
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}
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for(int i=0;i<4;i++)//一个节点可以走的四个方向，
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{
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B.x=A.x+d[i][0];
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B.y=A.y+d[i][1];
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if(B.x>=0&&B.x<n&&B.y>=0&&B.y<m&&dis[B.x][B.y]==0&&ch[B.x][B.y]!='#')//判断这一步能不能走；
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{
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if(ch[B.x][B.y]=='x') B.step=A.step+2;
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else B.step=A.step+1;
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dis[B.x][B.y]=1;//这个点已经走过，所以要标记下来；
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que.push(B);//把走的这个节点放进队列里面；
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}
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}
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}
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if(cnt == -1) puts("Poor ANGEL has to stay in the prison all his life.");
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else
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printf("%d\n", cnt);
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}
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int main()
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{
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while(~scanf("%d %d",&n,&m ))
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{
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A.step=0;
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B.step=0;
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memset(dis,0,sizeof(dis));
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for(int i=0;i<n;i++)
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scanf("%s",ch[i]);
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for(int i=0;i<n;i++)
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{
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for(int j=0;j<m;j++)
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{
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if(ch[i][j]=='a')
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{
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edx=i;
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edy=j;
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}
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if(ch[i][j]=='r')
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{
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enx=i;
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eny=j;
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}
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}
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}
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bfs(edx,edy);
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}
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return 0;
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}
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