实现功能:首先输入一个长度为N的序列,由1-4组成(1表示向前滚一下,2表示向后滚一下,3表示向左滚一下,4表示向右滚一下,骰子原始状态:上1前2左4右5后3下6),然后输入任意多个操作,输入“1 x y”表示将序列第x个数改成y,输入“2 x y”表示输出对于原始状态的骰子,按照从x到y的序列操作可以使骰子变成什么样子
原理:还是线段树,而且只需要点修改区间访问,不过这里面区间之间的合并不再是简单的累加了,而是——置换关系,通过置换关系的合并实现及时的维护即可
1 type 2 cube=array[1..6] of longint; 3 const fo:cube=(3,1,6,4,5,2); 4 ba:cube=(2,6,1,4,5,3); 5 le:cube=(5,2,3,1,6,4); 6 ri:cube=(4,2,3,6,1,5); 7 mo:cube=(1,2,3,4,5,6); 8 var 9 i,j,k,l,m,n:longint; 10 a:array[0..1000000] of cube; 11 a1:cube; 12 function min(x,y:longint):longint;inline; 13 begin 14 if x<y then min:=x else min:=y; 15 end; 16 function max(x,y:longint):longint;inline; 17 begin 18 if x>y then max:=x else max:=y; 19 end; 20 21 function merge(a1,a2:cube):cube;inline; 22 var a3:cube;i:longint; 23 begin 24 for i:=1 to 6 do 25 a3[i]:=a1[a2[i]]; 26 exit(a3); 27 end; 28 procedure built(z,x,y:longint);inline; 29 begin 30 if x=y then 31 begin 32 read(i); 33 case i of 34 1:a[z]:=fo; 35 2:a[z]:=ba; 36 3:a[z]:=le; 37 4:a[z]:=ri; 38 end; 39 end 40 else 41 begin 42 built(z*2,x,(x+y) div 2); 43 built(z*2+1,(x+y) div 2+1,y); 44 a[z]:=merge(a[z*2],a[z*2+1]); 45 end; 46 end; 47 procedure op(z,x,y,t,v:longint);inline; 48 begin 49 if (t=y) and (x=t) then 50 begin 51 case v of 52 1:a[z]:=fo; 53 2:a[z]:=ba; 54 3:a[z]:=le; 55 4:a[z]:=ri; 56 end; 57 exit; 58 end; 59 if t<=(x+y) div 2 then op(z*2,x,(x+y) div 2,t,v) else op(z*2+1,(x+y) div 2+1,y,t,v); 60 a[z]:=merge(a[z*2],a[z*2+1]); 61 end; 62 function res(z,x,y,l,r:longint):cube;inline; 63 begin 64 if (l>r) then exit(mo); 65 if (x=l) and (y=r) then exit(a[z]); 66 exit(merge(result(z*2,x,(x+y) div 2,l,min((x+y) div 2,r)),result(z*2+1,(x+y) div 2+1,y,max((x+y) div 2+1,l),r))); 67 end; 68 begin 69 readln(n); 70 built(1,1,n); 71 readln; 72 while true do 73 begin 74 read(i); 75 case i of 76 1:begin 77 readln(j,k); 78 op(1,1,n,j,k); 79 end; 80 2:begin 81 readln(j,k); 82 a1:=res(1,1,n,j,k); 83 for i:=1 to 6 do write(a1[i],‘ ‘); 84 writeln; 85 end; 86 end; 87 end; 88 89 end. 90
原文:http://www.cnblogs.com/HansBug/p/4287142.html