超级记事簿([IOI2012]龙虾抄写器-字典树)

超级记事本([IOI2012]龙虾抄写器-字典树)

我记得以前写过一道题和这个一样。。。

时隔一年，，自己的Trie树究竟长进多少？

#include<cstdio>#include<cstdlib>#include<cstring>#include<iostream>#include<algorithm>#include<functional>#include<cmath>#include<cctype>#include<cassert>#include<climits>using namespace std;#define For(i,n) for(int i=1;i<=n;i++)#define Rep(i,n) for(int i=0;i<n;i++)#define Fork(i,k,n) for(int i=k;i<=n;i++)#define ForD(i,n) for(int i=n;i;i--)#define Forp(x) for(int p=pre[x];p;p=next[p])#define RepD(i,n) for(int i=n;i>=0;i--)#define MEM(a) memset(a,0,sizeof(a));#define MEMI(a) memset(a,127,sizeof(a));#define MEMi(a) memset(a,128,sizeof(a));#define INF (2139062143)#define F (1000000009)#define MAXN (100000+10)#define LogMAXN (20+10)typedef long long ll;struct Tnode{   char c;   int fa[LogMAXN],deep;   Tnode():deep(0){MEM(fa) }   Tnode(char _c,int _fa,int _deep):c(_c),deep(_deep){MEM(fa) fa[0]=_fa;}}a[MAXN];int n,tot=1;void msm(int t){   for(int i=1;a[t].fa[i-1];i++)      a[t].fa[i]=a[a[t].fa[i-1]].fa[i-1];}void type(char c){   tot++;   a[tot]=Tnode(c,tot-1,a[tot-1].deep+1);msm(tot);}void query(int p){   p=a[tot].deep-p;   int now=tot;   while(p)   {      int t=(int)(trunc(log2(p)));      now=a[now].fa[t];      p-=1<<t;   }   printf("%c\n",a[now].c);}void undo(int p){   tot++;   a[tot]=a[tot-1-p];}int main(){   freopen("spnp.in","r",stdin);   freopen("spnp.out","w",stdout);   scanf("%d",&n);   For(i,n)   {      char s[2],c;int p;      scanf("%s",s);      switch(s[0])      {         case'T':scanf(" %c",&c);type(c);break;         case'Q':scanf(" %d",&p);query(p);break;         default:scanf(" %d",&p);undo(p);break;      }   }   // while(1);   return 0;}