delete pics to save space

2.1601.cpp

@@ -0,0 +1,92 @@
+#include<cstdio>
+#include<cstring>
+#include<cctype>
+#include<queue>
+using namespace std;
+const int maxs=20;
+const int maxn=150;
+const int dx[]={1,-1,0,0,0};
+const int dy[]={0,0,1,-1,0};
+inline int ID(int a,int b,int c)
+{
+	return (a<<16)|(b<<8)|c;
+}
+int s[3],t[3];
+int deg[maxn],G[maxn][5];
+inline bool error(int a, int b, int a2, int b2)
+{
+	return a2==b2||(a2==b&&b2==a);
+}
+int d[maxn][maxn][maxn];
+int bfs()
+{
+	queue<int> q;
+	memset(d,-1,sizeof(d));
+	q.push(ID(s[0],s[1],s[2]));
+	d[s[0]][s[1]][s[2]]=0;
+	while(!q.empty())
+	{
+		int u=q.front();
+		q.pop();
+		int a=(u>>16)&0xff,b=(u>>8)&0xff,c=u&0xff;
+		if(a==t[0]&&b==t[1]&&c==t[2]) return d[a][b][c];
+		for(int i=0;i<deg[a];i++)
+		{
+			int a2=G[a][i];
+			for(int j=0;j<deg[b];j++)
+			{
+				int b2=G[b][j];
+				if(error(a,b,a2,b2)) continue;
+				for(int k=0;k<deg[c];k++)
+				{
+					int c2=G[c][k];
+					if(error(a,c,a2,c2)) continue;
+					if(error(b,c,b2,c2)) continue;
+					if(d[a2][b2][c2]!=-1) continue;
+					d[a2][b2][c2]=d[a][b][c]+1;
+					q.push(ID(a2,b2,c2));
+				}
+			}
+		}
+	}
+	return -1;
+}
+int main()
+{
+#ifdef local
+	freopen("pro.in","r",stdin);
+#endif
+	int w,h,n; 
+	while(scanf("%d%d%d\n",&w,&h,&n)==3&&n)
+	{
+		char maze[20][20];
+		for(int i=0;i<h;i++)
+			fgets(maze[i], 20, stdin);
+		int cnt,x[maxn],y[maxn],id[maxs][maxs];
+		cnt=0;
+		for(int i=0;i<h;i++)
+			for(int j=0;j<w;j++)
+				if(maze[i][j]!='#')
+				{
+					x[cnt]=i;
+					y[cnt]=j;
+					id[i][j]=cnt;
+					if(islower(maze[i][j])) s[maze[i][j]-'a']=cnt;
+					else if(isupper(maze[i][j])) t[maze[i][j]-'A']=cnt;
+					cnt++;
+				}
+		for(int i=0;i<cnt;i++)
+		{
+			deg[i]=0;
+			for(int j=0;j<5;j++)
+			{
+				int nx=x[i]+dx[j],ny=y[i]+dy[j];
+				if(maze[nx][ny]!='#') G[i][deg[i]++]=id[nx][ny];
+			}
+		}
+		if(n<=2) { deg[cnt] = 1; G[cnt][0] = cnt; s[2] = t[2] = cnt++; }
+		if(n<=1) { deg[cnt] = 1; G[cnt][0] = cnt; s[1] = t[1] = cnt++; }
+		printf("%d\n", bfs());
+	}
+	return 0;
+}