Bzoj 3205: [Apio2013] Robot "dfs+ Steiner Tree +SPFA"

The first time I heard of the Steiner tree.
First DFS preprocessing out dis[i][j][k] means that the lattice (i,j) to the direction of the K transfer can be, memory word search preprocessing, note if there is a ring, special sentence
Set F[i][j][x][y] means that the composite robot i-j (x, y) generation need to push the number of steps, with SPFA transfer, because the time is tight, so optimize the SPFA, put the can transfer into a queue (exactly the stack) by F Sort, SPFA transferred to the other, Get the first small update answer for each team

#include <iostream>#include <cstdio>#include <cstring>#include <queue>using namespaceStdConst intn=505, m=600003, dx[]={0,1,0,-1},dy[]={1,0,-1,0};intn,h,w,f[Ten][Ten][n][n],v[n][n][5],ti,s[m+5],va[n*n],top,inf;BOOLMk[n][n];CharC[n][n];structqwe{intx, y; Qwe (intx=0,inty=0) {x=x,y=y; }}dis[n][n][5],q[n*n],p[m+5];qwe DFS (intXintYintK) {if(V[x][y][k]==ti)returnQwe (-1,0); V[x][y][k]=ti;if(dis[x][y][k].x!=0)returnDIS[X][Y][K];intT=k;if(c[x][y]==' C ') k= (k+1)%4;if(c[x][y]==' A ') k= (k+3)%4;intXX=X+DX[K],YY=Y+DY[K];if(xx>w| | xx<1|| yy>h| | yy<1|| c[xx][yy]==' x ')returnDis[x][y][t]=qwe (x, y);returnDis[x][y][t]=dfs (xx,yy,k);}voidSPFA (intLintR) {memset (s),0,sizeof(s)); Memset (MK,0,sizeof(MK));intMn=inf,mx=-inf; for(intI=1; i<=top;i++) {s[va[i]]++;if(VA[I]&LT;MN) mn=va[i];if(VA[I]&GT;MX) mx=va[i]; mk[q[i].x][q[i].y]=1; } for(intI=mn+1; i<=mx;i++) S[i]+=s[i-1]; for(intI=1; i<=top;i++) P[s[va[i]]--]=q[i]; for(intI=1; i<=top;i++) Q[i]=p[top-i+1];intLl=0, rr=0; while(top| | LL!=RR) {intNow=ll%m+1; Qwe u;if(ll==rr| |            (Top&&f[l][r][q[top].x][q[top].y]<f[l][r][p[now].x][p[now].y])) u=q[top--];ElseU=p[ll=now];intX=U.X,Y=U.Y; mk[x][y]=0; for(intI=0;i<4; i++) {intTX=DIS[X][Y][I].X,TY=DIS[X][Y][I].Y;if(tx!=-1&&f[l][r][x][y]+1<f[l][r][tx][ty]) {F[l][r][tx][ty]=f[l][r][x][y]+1;if(!mk[tx][ty]) {mk[tx][ty]=1; P[rr=rr%m+1]=qwe (Tx,ty); }            }        }    }}intMain () {scanf ("%d%d%d", &n,&h,&w); for(intI=1; i<=w;i++) scanf ("%s", C[i]+1); Memset (F,127/3,sizeof(f)); inf=f[0][0][0][0];cerr<<inf<<endl; for(intI=1; i<=w;i++) for(intj=1; j<=h;j++)if(c[i][j]!=' x ') for(intk=0;k<4; k++) Ti++,dis[i][j][k]=dfs (i,j,k); for(intI=1; i<=w;i++) for(intj=1; j<=h;j++)if(c[i][j]>=' 0 '&&c[i][j]<=' 9 ') F[c[i][j]-48][C[I][J]-48][i][j]=0; for(intL=1; l<=n;l++) for(intx=1; x<=n-l+1; x + +) {intY=x+l-1; top=0; for(intI=1; i<=w;i++) for(intj=1; j<=h;j++) { for(intk=x;k<y;k++)if(f[x][y][i][j]>f[x][k][i][j]+f[k+1][Y][I][J]) f[x][y][i][j]=f[x][k][i][j]+f[k+1][Y][I][J];if(F[x][y][i][j]!=inf)                        {q[++top]=qwe (I,J);                    VA[TOP]=F[X][Y][I][J];        }} SPFA (x, y); }intAns=inf; for(intI=1; i<=w;i++) for(intj=1; j<=h;j++)if(f[1][n][i][j]<ans) ans=f[1][N][I][J]; printf"%d\n", Ans==inf?-1: ans);return 0;}

Bzoj 3205: [Apio2013] Robot "dfs+ Steiner Tree +SPFA"