BZOJ1524: [POI2006]Pal

  1 #include<cstdio>
  2 
  3 #include<cstdlib>
  4 
  5 #include<cmath>
  6 
  7 #include<cstring>
  8 
  9 #include<algorithm>
 10 
 11 #include<iostream>
 12 
 13 #include<vector>
 14 
 15 #include<map>
 16 
 17 #include<set>
 18 
 19 #include<queue>
 20 
 21 #include<string>
 22 
 23 #define inf 1000000000
 24 
 25 #define maxn 2000000+10
 26 
 27 #define maxm 2000000
 28 
 29 #define eps 1e-10
 30 
 31 #define ll long long
 32 
 33 #define pa pair<int,int>
 34 
 35 #define for0(i,n) for(int i=0;i<=(n);i++)
 36 
 37 #define for1(i,n) for(int i=1;i<=(n);i++)
 38 
 39 #define for2(i,x,y) for(int i=(x);i<=(y);i++)
 40 
 41 #define for3(i,x,y) for(int i=(x);i>=(y);i--)
 42 
 43 #define mod 1000000007
 44 #define base 131
 45 
 46 using namespace std;
 47 
 48 inline int read()
 49 
 50 {
 51 
 52     int x=0,f=1;char ch=getchar();
 53 
 54     while(ch<‘0‘||ch>‘9‘){if(ch==‘-‘)f=-1;ch=getchar();}
 55 
 56     while(ch>=‘0‘&&ch<=‘9‘){x=10*x+ch-‘0‘;ch=getchar();}
 57 
 58     return x*f;
 59 
 60 }
 61 int n,tot,t[maxn][27],g[maxn],len[maxm];
 62 ll f[maxn],h[maxn],ans,ha[maxm];
 63 char s[maxn];
 64 string st[maxm];
 65 
 66 int main()
 67 
 68 {
 69 
 70     freopen("input.txt","r",stdin);
 71 
 72     freopen("output.txt","w",stdout);
 73     h[0]=1;
 74     for1(i,maxn)h[i]=h[i-1]*base;
 75 
 76     n=read();ans=-n;
 77     for1(k,n)
 78     {
 79         len[k]=read();
 80         scanf("%s",s+1);st[k]=s+1;
 81         int now=0;ll hash=0;
 82         for1(i,len[k])
 83          {
 84              int x=s[i]-‘a‘+1;
 85              if(!t[now][x])t[now][x]=++tot;
 86              now=t[now][x];
 87              hash=hash*base+x;
 88          }
 89         ha[k]=hash; 
 90         f[now]=k;g[now]++;
 91     }
 92     for1(k,n)
 93     {
 94         int now=0; 
 95         for0(i,len[k]-1) 
 96          {
 97              int x=st[k][i]-‘a‘+1;
 98              now=t[now][x];
 99              if(g[now]&&ha[f[now]]*h[len[k]]+ha[k]==ha[k]*h[i+1]+ha[f[now]])ans+=(ll)g[now]*2;
100          }
101     }
102     printf("%lld\n",ans);
103 
104     return 0;
105 
106 }