P4421 [COCI2017-2018#1] Lozinke
题面:https://www.luogu.org/problem/P4421
本题把所有可能的子串全部做一遍字符串哈希,然后判断一波即可.
Code:
#include<iostream>
#include<algorithm>
#include<cstdio>
#include<cstdlib>
#include<cmath>
#include<cstring>
#include<queue>
#include<set>
using namespace std;
const int N=1000005;
int n,base=26,len;
long long hash[N],order[N],ans;
string a[N];
set<long long> Q;
int main(){
cin>>n;
for(int i=1;i<=n;i++){
cin>>a[i];
}
for(int i=1;i<=n;i++){
int num=0;
for(int j=0;j<a[i].size();j++){
long long Hash=a[i][j]-'a'+1;
hash[++num]=Hash;
for(int k=j+1;k<a[i].size();k++){
Hash=Hash*base+a[i][k]-'a'+1;
hash[++num]=Hash;
}
}
sort(hash+1,hash+1+num);
for(int j=1;j<=num;j++){
if(hash[j]!=hash[j-1]){
order[++len]=hash[j];
}
}
}
sort(order+1,order+1+len);
for(int i=1;i<=n;i++){
long long Hash=a[i][0]-'a'+1;
for (int j=1;j<a[i].size();j++){
Hash=Hash*base+a[i][j]-'a'+1;
}
int pos=lower_bound(order+1,order+1+len,Hash)-order;
while(order[pos]==Hash){
ans++;
pos++;
}
}
printf("%lld\n",ans-n);
return 0;
}