GYM 100685 K

比眉伴天荒 2022-08-04 14:41 111阅读 0赞

乱搞题  
统计每一个不是magic word的单词，然后每个make\_pair  
然后按照公式计算答案。  
因为这里是乱序的统计make\_pair的情况，所以如果相邻的是相同的就会多统计一倍，在计算答案的是就要去掉，如果你保证字典序小的在前面，那就无所谓啦。

// whn6325689
    // Mr.Phoebe
    // http://blog.csdn.net/u013007900
    #include <algorithm>
    #include <iostream>
    #include <iomanip>
    #include <cstring>
    #include <climits>
    #include <complex>
    #include <fstream>
    #include <cassert>
    #include <cstdio>
    #include <bitset>
    #include <vector>
    #include <deque>
    #include <queue>
    #include <stack>
    #include <ctime>
    #include <set>
    #include <map>
    #include <cmath>
    #include <functional>
    #include <numeric>
    #pragma comment(linker, "/STACK:1024000000,1024000000")
    
    
    using namespace std;
    
    #define eps 1e-9
    #define PI acos(-1.0)
    #define INF 0x3f3f3f3f
    #define LLINF 1LL<<62
    #define speed std::ios::sync_with_stdio(false);
    
    typedef long long ll;
    typedef unsigned long long ull;
    typedef long double ld;
    typedef pair<ll, ll> pll;
    typedef complex<ld> point;
    typedef pair<int, int> pii;
    typedef pair<pii, int> piii;
    typedef vector<int> vi;
    
    #define CLR(x,y) memset(x,y,sizeof(x))
    #define CPY(x,y) memcpy(x,y,sizeof(x))
    #define clr(a,x,size) memset(a,x,sizeof(a[0])*(size))
    #define cpy(a,x,size) memcpy(a,x,sizeof(a[0])*(size))
    #define debug(a) cout << #a" = " << (a) << endl;
    #define debugarry(a, n) for (int i = 0; i < (n); i++) { cout << #a"[" << i << "] = " << (a)[i] << endl; }
    
    #define mp(x,y) make_pair(x,y)
    #define pb(x) push_back(x)
    #define lowbit(x) (x&(-x))
    
    #define MID(x,y) (x+((y-x)>>1))
    #define ls (idx<<1)
    #define rs (idx<<1|1)
    #define lson ls,l,mid
    #define rson rs,mid+1,r
    
    template<class T>
    inline bool read(T &n)
    {
        T x = 0, tmp = 1;
        char c = getchar();
        while((c < '0' || c > '9') && c != '-' && c != EOF) c = getchar();
        if(c == EOF) return false;
        if(c == '-') c = getchar(), tmp = -1;
        while(c >= '0' && c <= '9') x *= 10, x += (c - '0'),c = getchar();
        n = x*tmp;
        return true;
    }
    template <class T>
    inline void write(T n)
    {
        if(n < 0)
        {
            putchar('-');
            n = -n;
        }
        int len = 0,data[20];
        while(n)
        {
            data[len++] = n%10;
            n /= 10;
        }
        if(!len) data[len++] = 0;
        while(len--) putchar(data[len]+48);
    }
    //-----------------------------------
    
    set<string> m;
    string str[4005];
    ll tot=0;
    map<string,ll> cnt;
    map<pair<string,string>,ll> cntp;
    string pre,now;
    int main()
    {
    //freopen("data.txt","r",stdin);
        speed
        int n,k,q;
        cin>>n;getline(cin,now);
        for(int i=1;i<=n;i++)
        {
            getline(cin,str[i]);
            for(int j=0;j<str[i].length();j++)
            {
                if('A'<=str[i][j] && str[i][j]<='Z')
                    str[i][j]-='A'-'a';
                if(!(str[i][j]>='a'&&str[i][j]<='z'))
                    str[i][j]=' ';
            }
        }
        cin>>k;
        while(k--)
        {
            cin>>now;
            m.insert(now);
        }
        stringstream ss;
        bool first=1;
        for(int i=1;i<=n;i++)
        {
            ss.str(str[i]);
            while(ss>>now)
            {
                if(m.find(now)==m.end())
                {
                    tot++;
                    cnt[now]++;
                    if(first)
                        first=0;
                    else
                    {
                        cntp[mp(pre,now)]++;
                        cntp[mp(now,pre)]++;
                    }
                    pre=now;
                }
            }
            ss.clear();
        }
        cin>>q;
        while(q--)
        {
            cin>>pre>>now;
            if(cntp.find(mp(pre,now))!=cntp.end())
            {
                double ans=1.0*tot*tot*(cntp[mp(pre,now)])/(1.0*cnt[pre]*cnt[now]*(tot-1));
                if(pre==now)    ans/=2.0;
                cout<<setiosflags(ios::fixed)<<setprecision(10)<<ans<<endl;
            }
            else
                cout<<"0.0000000000"<<endl;
        }
        return 0;
    }