超级大逃亡

时隔多年，终于搞定

思路：看代码

#include<cstdio>#include<cstring>#include<cstdlib>int n,m,l,r;char map[70][70];char cur[70][70];int X,Y;struct my{int x,y;};int pre[70][70];my q[10000];long long ans=0;bool b[70][70];char c[100];int cc;long long get(int x,int y){if (x==1 && y==1)return 0;if (pre[x][y]==1)return 1+3*get(x-1,y);elsereturn 2+3*get(x,y-1);}void p(int x,int y){if (x==1 && y==1){cc=0;return;}if (pre[x][y]==1)p(x-1,y),c[cc++]='D';elsep(x,y-1),c[cc++]='R';}void bfs(){int i,j,k;for (i=1;i<=X+1;i++)for (j=1;j<=Y+1;j++)cur[i][j]='.',b[i][j]=false;int ii=1,jj=1;int N=X+1,M=Y+1;while (ii+X<=n && jj+Y<=m){/*for (i=ii;i<=ii+X;i++)for (j=ii;j<=ii+Y;j++)if (map[i][j]=='X')cur[i-ii+1][j-jj+1]='X',cout<<"here"<<i<<' '<<j<<' '<<ii<<' '<<jj<<endl;*/for (i=1;i<=N;i++)for (j=1;j<=M;j++)if (map[i+ii-1][j+jj-1]=='X')cur[i][j]='X';if (cur[X+1][Y+1]=='Y')return;ii+=X;jj+=Y;}if (ii!=n && jj!=m)for (i=1;i<=N;i++)for (j=1;j<=M;j++)if (i+ii-1<=n && j+jj-1<=m && map[i+ii-1][j+jj-1]=='X')cur[i][j]='X';int start=0,end=1;q[0].x=q[0].y=1;if (cur[1][1]=='X')return;while (start<end){if (q[start].x==N && q[start].y==M){if (!ans)ans=get(q[start].x,q[start].y),p(N,M);else{long long cc=get(q[start].x,q[start].y);if (cc<ans){ans=cc;p(q[start].x,q[start].y);}}return;}if (q[start].x<N && cur[q[start].x+1][q[start].y]!='X' && !b[q[start].x+1][q[start].y]){b[q[start].x+1][q[start].y]=true;q[start].x++;q[end++]=q[start];q[start].x--;pre[q[start].x+1][q[start].y]=1;}if (q[start].y<M && cur[q[start].x][q[start].y+1]!='X' && !b[q[start].x][q[start].y+1]){b[q[start].x][q[start].y+1]=true;q[start].y++;q[end++]=q[start];pre[q[start].x][q[start].y]=2;}start++;}}void f(int num){int i,j,x,y,temp=num>n?n:num;for (x=0;x<=temp;++x){y=num-x;if (y>m)continue;X=x;Y=y;bfs();}}int main(){//freopen("in.txt","r",stdin);int i,j,k;int t;scanf("%d",&t);//memset(map,'X',sizeof(map));while (t--){ans=0;scanf("%d%d%d%d",&n,&m,&l,&r);getchar();for (i=1;i<=n;++i)scanf("%s",map[i]+1);for (i=l;i<=r;i++){f(i);if (ans)break;}c[i]='\0';puts(c);}return 0;}