题目分析：
集合双Hash
1 #include<bits/stdc++.h> 2 #define Mod1 1000000009 3 #define Mod2 1000000007 4 #define maxn 510 5 #define LL long long 6 #define mp make_pair 7 #define Pii pair<LL,LL> 8 #define fi first 9 #define se second 10 #define push_back 11 using namespace std; 12 LL hash1[maxn],hash2[maxn]; 13 int n,seg[maxn]; 14 LL ksm(LL base,LL m,LL mod){ 15 LL res=1; 16 while(m){ 17 if(m&1) res=(res*base)%mod; 18 base=(base*base)%mod; 19 m>>=1; 20 } 21 return res; 22 } 23 void pre_hash(){ 24 int ans1=0,ans2=0; 25 for(int i=0;i<=500;i++){ 26 hash1[i]=ksm(i,i+5,Mod1); 27 hash2[i]=ksm(i,i+5,Mod2); 28 } 29 } 30 Pii getHash(set<int> &str){ 31 set<int>::iterator it; 32 LL ans1=0,ans2=0; 33 for(it=str.begin();it!=str.end();++it){ 34 ans1=(ans1+hash1[*it])%Mod1; 35 ans2=(ans2+hash2[*it])%Mod2; 36 } 37 return mp(ans1,ans2); 38 } 39 set<int> s; 40 set<Pii> ss; 41 int main(){ 42 freopen("numbereater.in","r",stdin); 43 freopen("numbereater.out","w",stdout); 44 pre_hash(); 45 cin>>n; 46 for(int i=1;i<=n;i++) scanf("%d",&seg[i]); 47 for(int i=1;i<=n;i++){ 48 s.clear(); 49 for(int j=i;j<=n;j++){ 50 s.insert(seg[j]); 51 ss.insert(getHash(s)); 52 } 53 } 54 cout<<ss.size(); 55 return 0; 56 }