UVALive3514,Cactus

这题我的想法是，对于连通图，求出点双之后，数一下每个 点双里的边数是否等于点数，就可以知道是否是仙人掌。然后将所有点数大于2的点双，ans∗=size+1
一开始求成边双了，感觉自己好智障

#include <cstdio>#include <cstdlib>#include <cstring>#include <string>#include <ctime>#include <iostream>#include <algorithm>#include <iomanip>#include <cmath>#include <vector>#include <queue>#include <map>#include <set>using namespace std;const int base = 1000000000;const int base_digits = 9;typedef long long ll;struct BigInt {    vector<int> a;    int sign;    BigInt() :        sign(1) {    }    BigInt(long long v) {        *this = v;    }    BigInt(const string &s) {        read(s);    }    void operator=(const BigInt &v) {        sign = v.sign;        a = v.a;    }    void operator=(long long v) {        sign = 1;        if (v < 0)            sign = -1, v = -v;        a.clear();        for (; v > 0; v = v / base)            a.push_back(v % base);    }    BigInt operator+(const BigInt &v) const {        if (sign == v.sign) {            BigInt res = v;            for (int i = 0, carry = 0; i < (int) max(a.size(), v.a.size()) || carry; ++i) {                if (i == (int) res.a.size())                    res.a.push_back(0);                res.a[i] += carry + (i < (int) a.size() ? a[i] : 0);                carry = res.a[i] >= base;                if (carry)                    res.a[i] -= base;            }            return res;        }        return *this - (-v);    }    BigInt operator-(const BigInt &v) const {        if (sign == v.sign) {            if (abs() >= v.abs()) {                BigInt res = *this;                for (int i = 0, carry = 0; i < (int) v.a.size() || carry; ++i) {                    res.a[i] -= carry + (i < (int) v.a.size() ? v.a[i] : 0);                    carry = res.a[i] < 0;                    if (carry)                        res.a[i] += base;                }                res.trim();                return res;            }            return -(v - *this);        }        return *this + (-v);    }    void operator*=(int v) {        if (v < 0)            sign = -sign, v = -v;        for (int i = 0, carry = 0; i < (int) a.size() || carry; ++i) {            if (i == (int) a.size())                a.push_back(0);            long long cur = a[i] * (long long) v + carry;            carry = (int) (cur / base);            a[i] = (int) (cur % base);            //asm("divl %%ecx" : "=a"(carry), "=d"(a[i]) : "A"(cur), "c"(base));        }        trim();    }    BigInt operator*(int v) const {        BigInt res = *this;        res *= v;        return res;    }    friend pair<BigInt, BigInt> divmod(const BigInt &a1, const BigInt &b1) {        int norm = base / (b1.a.back() + 1);        BigInt a = a1.abs() * norm;        BigInt b = b1.abs() * norm;        BigInt q, r;        q.a.resize(a.a.size());        for (int i = a.a.size() - 1; i >= 0; i--) {            r *= base;            r += a.a[i];            int s1 = r.a.size() <= b.a.size() ? 0 : r.a[b.a.size()];            int s2 = r.a.size() <= b.a.size() - 1 ? 0 : r.a[b.a.size() - 1];            int d = ((long long) base * s1 + s2) / b.a.back();            r -= b * d;            while (r < 0)                r += b, --d;            q.a[i] = d;        }        q.sign = a1.sign * b1.sign;        r.sign = a1.sign;        q.trim();        r.trim();        return make_pair(q, r / norm);    }    friend BigInt sqrt(const BigInt &a1) {        BigInt a = a1;        while (a.a.empty() || a.a.size() % 2 == 1)            a.a.push_back(0);        int n = a.a.size();        int firstDigit = (int) sqrt((double) a.a[n - 1] * base + a.a[n - 2]);        int norm = base / (firstDigit + 1);        a *= norm;        a *= norm;        while (a.a.empty() || a.a.size() % 2 == 1)            a.a.push_back(0);        BigInt r = (long long) a.a[n - 1] * base + a.a[n - 2];        firstDigit = (int) sqrt((double) a.a[n - 1] * base + a.a[n - 2]);        int q = firstDigit;        BigInt res;        for(int j = n / 2 - 1; j >= 0; j--) {            for(; ; --q) {                BigInt r1 = (r - (res * 2 * base + q) * q) * base * base + (j > 0 ? (long long) a.a[2 * j - 1] * base + a.a[2 * j - 2] : 0);                if (r1 >= 0) {                    r = r1;                    break;                }            }            res *= base;            res += q;            if (j > 0) {                int d1 = res.a.size() + 2 < r.a.size() ? r.a[res.a.size() + 2] : 0;                int d2 = res.a.size() + 1 < r.a.size() ? r.a[res.a.size() + 1] : 0;                int d3 = res.a.size() < r.a.size() ? r.a[res.a.size()] : 0;                q = ((long long) d1 * base * base + (long long) d2 * base + d3) / (firstDigit * 2);            }        }        res.trim();        return res / norm;    }    BigInt operator/(const BigInt &v) const {        return divmod(*this, v).first;    }    BigInt operator%(const BigInt &v) const {        return divmod(*this, v).second;    }    void operator/=(int v) {        if (v < 0)            sign = -sign, v = -v;        for (int i = (int) a.size() - 1, rem = 0; i >= 0; --i) {            long long cur = a[i] + rem * (long long) base;            a[i] = (int) (cur / v);            rem = (int) (cur % v);        }        trim();    }    BigInt operator/(int v) const {        BigInt res = *this;        res /= v;        return res;    }    int operator%(int v) const {        if (v < 0)            v = -v;        int m = 0;        for (int i = a.size() - 1; i >= 0; --i)            m = (a[i] + m * (long long) base) % v;        return m * sign;    }    void operator+=(const BigInt &v) {        *this = *this + v;    }    void operator-=(const BigInt &v) {        *this = *this - v;    }    void operator*=(const BigInt &v) {        *this = *this * v;    }    void operator/=(const BigInt &v) {        *this = *this / v;    }    bool operator<(const BigInt &v) const {        if (sign != v.sign)            return sign < v.sign;        if (a.size() != v.a.size())            return a.size() * sign < v.a.size() * v.sign;        for (int i = a.size() - 1; i >= 0; i--)            if (a[i] != v.a[i])                return a[i] * sign < v.a[i] * sign;        return false;    }    bool operator>(const BigInt &v) const {        return v < *this;    }    bool operator<=(const BigInt &v) const {        return !(v < *this);    }    bool operator>=(const BigInt &v) const {        return !(*this < v);    }    bool operator==(const BigInt &v) const {        return !(*this < v) && !(v < *this);    }    bool operator!=(const BigInt &v) const {        return *this < v || v < *this;    }    void trim() {        while (!a.empty() && !a.back())            a.pop_back();        if (a.empty())            sign = 1;    }    bool isZero() const {        return a.empty() || (a.size() == 1 && !a[0]);    }    BigInt operator-() const {        BigInt res = *this;        res.sign = -sign;        return res;    }    BigInt abs() const {        BigInt res = *this;        res.sign *= res.sign;        return res;    }    long long longValue() const {        long long res = 0;        for (int i = a.size() - 1; i >= 0; i--)            res = res * base + a[i];        return res * sign;    }    friend BigInt gcd(const BigInt &a, const BigInt &b) {        return b.isZero() ? a : gcd(b, a % b);    }    friend BigInt lcm(const BigInt &a, const BigInt &b) {        return a / gcd(a, b) * b;    }    void read(const string &s) {        sign = 1;        a.clear();        int pos = 0;        while (pos < (int) s.size() && (s[pos] == '-' || s[pos] == '+')) {            if (s[pos] == '-')                sign = -sign;            ++pos;        }        for (int i = s.size() - 1; i >= pos; i -= base_digits) {            int x = 0;            for (int j = max(pos, i - base_digits + 1); j <= i; j++)                x = x * 10 + s[j] - '0';            a.push_back(x);        }        trim();    }    friend istream& operator>>(istream &stream, BigInt &v) {        string s;        stream >> s;        v.read(s);        return stream;    }    friend ostream& operator<<(ostream &stream, const BigInt &v) {        if (v.sign == -1 && !v.isZero())            stream << '-';        stream << (v.a.empty() ? 0 : v.a.back());        for (int i = (int) v.a.size() - 2; i >= 0; --i)            stream << setw(base_digits) << setfill('0') << v.a[i];        return stream;    }    static vector<int> convert_base(const vector<int> &a, int old_digits, int new_digits) {        vector<long long> p(max(old_digits, new_digits) + 1);        p[0] = 1;        for (int i = 1; i < (int) p.size(); i++)            p[i] = p[i - 1] * 10;        vector<int> res;        long long cur = 0;        int cur_digits = 0;        for (int i = 0; i < (int) a.size(); i++) {            cur += a[i] * p[cur_digits];            cur_digits += old_digits;            while (cur_digits >= new_digits) {                res.push_back(int(cur % p[new_digits]));                cur /= p[new_digits];                cur_digits -= new_digits;            }        }        res.push_back((int) cur);        while (!res.empty() && !res.back())            res.pop_back();        return res;    }    typedef vector<long long> vll;    static vll karatsubaMultiply(const vll &a, const vll &b) {        int n = a.size();        vll res(n + n);        if (n <= 32) {            for (int i = 0; i < n; i++)                for (int j = 0; j < n; j++)                    res[i + j] += a[i] * b[j];            return res;        }        int k = n >> 1;        vll a1(a.begin(), a.begin() + k);        vll a2(a.begin() + k, a.end());        vll b1(b.begin(), b.begin() + k);        vll b2(b.begin() + k, b.end());        vll a1b1 = karatsubaMultiply(a1, b1);        vll a2b2 = karatsubaMultiply(a2, b2);        for (int i = 0; i < k; i++)            a2[i] += a1[i];        for (int i = 0; i < k; i++)            b2[i] += b1[i];        vll r = karatsubaMultiply(a2, b2);        for (int i = 0; i < (int) a1b1.size(); i++)            r[i] -= a1b1[i];        for (int i = 0; i < (int) a2b2.size(); i++)            r[i] -= a2b2[i];        for (int i = 0; i < (int) r.size(); i++)            res[i + k] += r[i];        for (int i = 0; i < (int) a1b1.size(); i++)            res[i] += a1b1[i];        for (int i = 0; i < (int) a2b2.size(); i++)            res[i + n] += a2b2[i];        return res;    }    BigInt operator*(const BigInt &v) const {        vector<int> a6 = convert_base(this->a, base_digits, 6);        vector<int> b6 = convert_base(v.a, base_digits, 6);        vll a(a6.begin(), a6.end());        vll b(b6.begin(), b6.end());        while (a.size() < b.size())            a.push_back(0);        while (b.size() < a.size())            b.push_back(0);        while (a.size() & (a.size() - 1))            a.push_back(0), b.push_back(0);        vll c = karatsubaMultiply(a, b);        BigInt res;        res.sign = sign * v.sign;        for (int i = 0, carry = 0; i < (int) c.size(); i++) {            long long cur = c[i] + carry;            res.a.push_back((int) (cur % 1000000));            carry = (int) (cur / 1000000);        }        res.a = convert_base(res.a, 6, base_digits);        res.trim();        return res;    }};const int A=250000;class graph{    private:        struct edge{            int to,next;            edge(int _to=0,int _next=0):to(_to),next(_next){}        }e[A<<2];        int h[A],v,i,dfn[A],low[A],tim,tail,xb;        edge st[A];        void dfs(int x,int fa){            tim++;            low[x]=dfn[x]=tim;            int child=0,s,t,i;            for (i=h[x];i;i=e[i].next){                int y=e[i].to;                if (!dfn[y]){                    child++;                    st[++tail]=edge(x,y);                    dfs(y,x);                    int w=low[y];                    if (w<low[x])low[x]=w;                    if (w>=dfn[x]){                        iscut[x]=1;                        bcc[++bcc_cnt].clear();                        for(;;){                            s=st[tail].to;                            t=st[tail--].next;                            if(bccno[s]!=bcc_cnt){                                bccno[s]=bcc_cnt;                                bcc[bcc_cnt].push_back(s);                            }                            if(bccno[t]!=bcc_cnt){                                bccno[t]=bcc_cnt;                                bcc[bcc_cnt].push_back(t);                            }                            if(s==x && t==y)break;                        }                    }                }else if (fa!=y && low[x]>dfn[y]){                    st[++tail]=edge(x,y);                    low[x]=dfn[y];                }            }            if (fa<0 && child==1)iscut[x]=0;        }    public:        int bcc_cnt,bccno[A];        vector<int> bcc[A];        bool iscut[A];        void init(int n){            v=n;            for(int i=1;i<=n;++i)h[i]=0;            xb=0;        }        void addedge(int x,int y){            e[++xb]=edge(y,h[x]);            h[x]=xb;        }        int tarjan(){            tim=bcc_cnt=tail=0;            for(int i=1;i<=v;++i){                bccno[i]=iscut[i]=dfn[i]=0;                bcc[i].clear();            }            int block=0;            for(int i=1;i<=v;++i)                if(!dfn[i])dfs(i,-1),++block;            return block;        }        bool iscactus(){            for(int i=1;i<=bcc_cnt;++i){                int s=0;                for(unsigned int k=0;k<bcc[i].size();++k)                    for(int j=h[bcc[i][k]];j;j=e[j].next)if(bccno[e[j].to]==i)++s;                if(s>(int)bcc[i].size()<<1)return 0;            }            return 1;        }}g;int n,m,x,y,i,k;BigInt ans;bool flag;set<pair<int,int> > s;int main(){     while(scanf("%d%d",&n,&m)!=EOF){        if(flag)putchar('\n');        flag=1;        g.init(n);        s.clear();        while(m--){            scanf("%d",&k);            scanf("%d",&x);            --k;            while(k--){                scanf("%d",&y);                if(x==y)continue;                if(!s.count(make_pair(x,y)))g.addedge(x,y),g.addedge(y,x),s.insert(make_pair(x,y));                x=y;            }        }        if(g.tarjan()>1){            puts("0");            continue;        }        if(!g.iscactus()){            puts("0");            continue;        }        ans=1;        for(i=1;i<=g.bcc_cnt;++i)if(g.bcc[i].size()>2)ans*=g.bcc[i].size()+1;        cout<<ans<<'\n';    }    return 0;}