POJ 2777(涂点问线）

线段树……

Program p2777;const   maxl=100000;   maxt=30;   maxo=100000;var   l,t,o,i,j,k:longint;   col:array[1..maxl*10] of longint;   c:char;   x,y,color:longint;   visit:array[1..maxt] of boolean;procedure build(l,r,root:longint);var   mid:longint;begin   if l=r then   begin      col[root]:=1;      exit;   end;   mid:=(l+r) shr 1;   build(l,mid,root shl  1);   build(mid+1,r,root shl 1+1);   col[root]:=1;end;procedure swap(var a,b:longint);var   p:longint;begin   p:=a;a:=b;b:=p;end;procedure detate(l,r,sonl,sonr,root,color:longint);var   i,j,mid:longint;begin   mid:=(l+r) shr 1;   if l=r then   begin      col[root]:=color;      exit;   end;   if (sonl<=l) and (r<=sonr) then   begin      col[root]:=color;      exit;   end;   if col[root]>0 then   begin      col[root*2]:=col[root];      col[root*2+1]:=col[root];      col[root]:=-1;   end;   if not((mid<sonl) or (sonr<l)) then detate(l,mid,sonl,sonr,root shl 1,color);   if not((r<sonl) or (sonr<mid+1)) then detate(mid+1,r,sonl,sonr,root shl 1+1,color);end;function quere(l,r,sonl,sonr,root:longint):longint;var   mid,i,j:longint;begin   quere:=0;   mid:=(l+r) shr 1;   if col[root]>0 then   begin      if not(visit[col[root]]) then      begin         visit[col[root]]:=true;         exit(1);      end;      exit(0);   end;   if not((mid<sonl) or (sonr<l)) then inc(quere,quere(l,mid,sonl,sonr,root shl 1));   if not((r<sonl) or (sonr<mid+1)) then inc(quere,quere(mid+1,r,sonl,sonr,root shl 1+1));end;begin   readln(l,t,o);   build(1,l,1);   for i:=1 to o do   begin      read(c);      if c='C' then      begin         readln(x,y,color);         if x>y then swap(x,y);         detate(1,l,x,y,1,color);      end      else      begin         readln(x,y);         if x>y then swap(x,y);         fillchar(visit,sizeof(visit),false);         writeln(quere(1,l,x,y,1));      end;   end;end.