字符串HASH模板

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单关键字字符串HASH：

typedef unsigned long long ull;
const ull base = 131;
struct My_Hash
{
    ull p[maxn],hs[maxn];
    void Insert( char s[] )
    {
        int len = strlen(s+1);
        p[0] = 1,hs[0] = 0;
        for ( int i=1 ; i<=len ; i++ )
            p[i] = p[i-1]*base,hs[i] = hs[i-1]*base+(ull)s[i];
    }
    ull GetHash( int l , int r )
    {
        return (ull)hs[r]-p[r-l+1]*hs[l-1];
    }
}S;

双关键字字符串HASH：

typedef unsigned long long ull;
const ull mod1 = 1e9+7;
const ull mod2 = 1e9+9;
const ull base1 = 131;
const ull base2 = 233;
struct My_Hash
{
    ull hs1[maxn],p1[maxn];
    ull hs2[maxn],p2[maxn];
    void Insert( char s[] )
    {
        int len = strlen(s+1);
        hs1[0] = 0,p1[0] = 1;
        hs2[0] = 0,p2[0] = 1;
        for ( int i=1 ; i<=len ; i++ )
        {
            p1[i] = p1[i-1]*base1%mod1;
            p2[i] = p2[i-1]*base2%mod2;
            hs1[i] = ( hs1[i-1]*base1%mod1+(ull)s[i] )%mod1;
            hs2[i] = ( hs2[i-1]*base2%mod2+(ull)s[i] )%mod2;
        }
    }
    pair<ull,ull> GetHash( int l , int r )
    {
        ull tmp1 = hs1[r];
        ull tmp2 = hs2[r];
        tmp1 = ( tmp1-p1[r-l+1]*hs1[l-1]%mod1+mod1 )%mod1;
        tmp2 = ( tmp2-p2[r-l+1]*hs2[l-1]%mod2+mod2 )%mod2;
        return make_pair( tmp1 , tmp2 );
    }
}S;