//TruncatedStepRowtemplate<size_t WIDTH> template<size_t W>TruncatedStepRow<WIDTH>::TruncatedStepRow(const TruncatedStepRow<W>& a, const TruncatedStepRow<W>& b, size_t len, size_t lenIndices, int lenTrim) :        StepRow<WIDTH> {a}{    cout<<"len="<<len<<endl;                            //30    cout<<"lenIndices="<<lenIndices<<endl;              //1 //   cout<<"lenTrim="<<lenTrim<<endl;                    //3    assert(len+lenIndices <= W);    assert(len-lenTrim+(2*lenIndices) <= WIDTH);//    unsigned char  hash[len-lenTrim];        cout<<"colision hash a =";    for(long long unsigned int i=0;i<len;i++){        cout<<a.hash[i];    }    cout<<endl;    cout<<"colision hash b =";    for(long long unsigned int i=0;i<len;i++){        cout<<b.hash[i];    }    cout<<endl;        for (int i = lenTrim; i < (int)len-lenTrim; i++){        hash[i-lenTrim] = a.hash[i] ^ a.hash[i];    } //    cout<<endl;    print_hash(len-lenTrim);    if (a.IndicesBefore(b, len, lenIndices)) {        std::copy(a.hash+len, a.hash+len+lenIndices, hash+len-lenTrim);        std::copy(b.hash+len, b.hash+len+lenIndices, hash+len-lenTrim+lenIndices);    } else {        std::copy(b.hash+len, b.hash+len+lenIndices, hash+len-lenTrim);        std::copy(a.hash+len, a.hash+len+lenIndices, hash+len-lenTrim+lenIndices);    }    //cout<<endl;    //cout<<endl;}相同的值异或应该是0才对，为什么输出还是4或者7 啊？？