poj 1330 Nearest Common Ancestors
题目大意
自己读~~真~题目大意
分析
就是裸的LCA tarjan离线算法,套模板。
代码
type arr=record x,y,w:longint; next:longint; end; var a,g:array[1..10010] of arr; fa,v,v1:array[1..10010] of longint; dis:array[1..10010] of int64; ls,ls1:array[1..10010] of longint; nm,nm1:longint; n,m:longint; i,j,k,l,z:longint; ans,ans2:int64; procedure add(x,y:longint); begin nm:=nm+1; a[nm].x:=x; a[nm].y:=y; //a[nm].w:=w; a[nm].next:=ls[x]; ls[x]:=nm; end; function find(x:longint):longint; begin if fa[x]=x then exit(x) else begin find:=find(fa[x]); fa[x]:=find; end; end; procedure union(x,y:longint); var i,j:longint; begin i:=find(x); j:=find(y); fa[i]:=j; end; procedure dfs(r:longint); var i,j,k:longint; begin i:=ls[r]; while i<>0 do begin with a[i] do begin dfs(y); union(y,x); v[y]:=1; i:=next; end; end; i:=ls1[r]; while i<>0 do begin with g[i] do begin if v[y]=1 then {if find(y)=x then begin ans:=ans+1; ans2:=ans2+dis[y]-dis[x]; end; } writeln(find(y)); i:=next; end; end; end; procedure di(r:longint); var i,j,k:longint; begin i:=ls[r]; while i<>0 do with a[i] do begin dis[y]:=dis[x]+w; di(y); i:=next; end; end; begin readln(m); for z:=1 to m do begin fillchar(ls,sizeof(ls),0); fillchar(ls1,sizeof(ls1),0); nm:=0; nm1:=0; fillchar(v,sizeof(v),0); fillchar(v1,sizeof(v1),0); readln(n); for i:=1 to n-1 do begin readln(j,k); add(j,k); v1[k]:=1; end; di(1); for i:=1 to 1 do begin readln(j,k); nm1:=nm1+1; g[nm1].x:=j; g[nm1].y:=k; g[nm1].next:=ls1[j]; ls1[j]:=nm1; nm1:=nm1+1; g[nm1].x:=k; g[nm1].y:=j; g[nm1].next:=ls1[k]; ls1[k]:=nm1; end; for i:=1 to n do fa[i]:=i; for i:=1 to n do if v1[i]=0 then dfs(i); {writeln(ans); writeln(ans2);} end; end.