题目源:http://agc012.contest.atcoder.jp/tasks/agc012_b 存边的方法我就不说了 这题的做法说白了就是强暴力+优化 染色从后往前染(不解释) 对于每个点,标记该点已染色的最大范围,搜到该点时,若还需染色的范围比标记小就不用染下去了 下面贴代码,注意数组要开两倍
type arr=array[0..200001]of longint; var n,q,m,i,j,a,b:longint; v,d,c,max,cl,head,next,start,endd:arr; bb,bc:array[0..200001]of boolean; procedure dfs(k,dis,col:longint); var i:longint; begin bb[k]:=true; if(max[k]>=dis)and(bc[k])then begin bb[k]:=false; exit; end; max[k]:=dis; if not bc[k]then begin cl[k]:=col; bc[k]:=true; end; if dis>0 then for i:=start[k] to endd[k] do if not bb[next[i]]then dfs(next[i],dis-1,col); bb[k]:=false; end; procedure sort(l,r:longint); var i,j,x,y:longint; begin i:=l;j:=r;x:=head[(l+r) div 2]; repeat while head[i]<x do inc(i); while x<head[j] do dec(j); if not(i>j) then begin y:=head[i];head[i]:=head[j];head[j]:=y; y:=next[i];next[i]:=next[j];next[j]:=y; inc(i);j:=j-1; end; until i>j; if l<j then sort(l,j); if i<r then sort(i,r); end; begin readln(n,m); fillchar(cl,sizeof(cl),0); fillchar(max,sizeof(max),0); fillchar(bb,sizeof(bb),false); fillchar(bc,sizeof(bc),false); for i:=1 to m do begin readln(a,b); head[i]:=a;head[i+m]:=b; next[i]:=b;next[i+m]:=a; end; m:=m*2;sort(1,m);start[head[1]]:=1; for i:=2 to m do if head[i]<>head[i-1]then begin endd[head[i-1]]:=i-1; start[head[i]]:=i; end; endd[head[m]]:=m; readln(q); for i:=q downto 1 do readln(v[i],d[i],c[i]); for i:=1 to q do dfs(v[i],d[i],c[i]); for i:=1 to n do writeln(cl[i]); end.