Codeforces A Serial Killer

/*
Lionel Messi is such a player that you may catch him, you may touch him, you may feel him
and definitely you may Love him.
Lionel Messi is Messi. A little Magician in this World.

*/

// Accepted

#include<bits/stdc++.h>

using namespace std;

#define fast ios_base::sync_with_stdio(0)
#define bfast cin.tie(0)
#define outs(x) cout << x << " "
#define outn(x) cout << x << "\n"
#define sf scanf
#define pf printf
#define nl puts("")
#define psb push_back
#define loop0(n) for(int i=0; i<n; i++)
#define loop1(n) for(int i=1; i<=n; i++)
#define mpair(x , y) make_pair(x , y)
#define all(x) x.begin(), x.end()
#define pi acos(-1.0)

typedef unsigned long long ull;
typedef long long LL;
typedef vector<int>vii;
typedef vector<LL>vll;
typedef vector<string>vs;
typedef map<int, int>mpii;
typedef map<string, int>mpsi;
typedef map<char, int>mpci;
typedef map<LL, LL>mpll;

const int mod = 1000007;
const int high = 10003;


struct printf
{
    void ek(int n){cout << n << "\n";}
    void dui(int x , int y) { cout << x << " " << y << "\n"; }
    void tin(int x , int y , int z) { cout << x << " " << y << " " << z << "\n"; }
}tp;

struct sieve
{
    int prm[high], plen=0;
    bitset<high>bs;
    void get_prime()
    {
        LL i , j;
        bs.set();
        bs[0]=bs[1]=0;
        for(i=2; i<=high; i++)
        {
            if(bs[i])
            {
                prm[plen++] = i;

                for(j=i*i; j<=high; j+=i) bs[j] = 0;
            }
        }
    }
    void pprm(){ for(int i=0; i<100; i++) cout << prm[i] << "; "; }
}prime;

pair<string, string>pstring[high];

int main()
{
    fast;
    int days=0;
    mpsi mp;
    vs v;
    int i=0 , len=0;
    string name1 , name2 , tmp;
    while(cin >> name1 >> name2)
    {
        mp.clear();
        v.clear();

        cin >> days;

        cout << name1 << " " << name2 << "\n";

        mp[name1] = 1;
        mp[name2] = 1;

        v.push_back(name1);
        v.push_back(name2);

        len=v.size();

        while(days--)
        {
            cin >> name1 >> name2;

            mp[name1] = 0;

            len = v.size();
            v.push_back(name2);

            for(i=0; i<len; i++)
            {
                if(mp[v[i]])
                {
                    cout << v[i] << " ";
                }
            }

            cout << name2 << "\n";

            mp[name2] = 1;
            //v.push_back(name2);
        }
    }

    return 0;
}

=====================     Fastest Solution  ====================================


/*
Lionel Messi is such a player that you may catch him, you may touch him, you may feel him
and definitely you may Love him.
Lionel Messi is Messi. A little Magician in this World.

*/

#include<bits/stdc++.h>

using namespace std;

#define fast ios_base::sync_with_stdio(0)
#define bfast cin.tie(0)
#define outs(x) cout << x << " "
#define outn(x) cout << x << "\n"
#define sf scanf
#define pf printf
#define nl puts("")
#define psb push_back
#define loop0(n) for(int i=0; i<n; i++)
#define loop1(n) for(int i=1; i<=n; i++)
#define mpair(x , y) make_pair(x , y)
#define all(x) x.begin(), x.end()
#define pi acos(-1.0)

typedef unsigned long long ull;
typedef long long LL;
typedef vector<int>vii;
typedef vector<LL>vll;
typedef map<int, int>mpii;
typedef map<string, int>mpsi;
typedef map<char, int>mpci;
typedef map<LL, LL>mpll;

const int mod = 1000007;
const int high = 100;

int main()
{
    fast;
    int days;
    string name1 , name2 , c , d;
    while(cin >> name1 >> name2)
    {
        cin >> days;

        cout << name1 << " " << name2 << "\n";

        while(days--)
        {
            cin >> c >> d;

            if(c == name1) name1 = name2 , name2 = d;
            else name2 = d;

            cout << name1 << " " << name2 << "\n";
        }
    }

    return 0;
}