1435B - A New Technique - CodeForces Solution

import sys
from sys import stdin

tt = int(stdin.readline())

ANS = []
for loop in range(tt):

    n,m = map(int,stdin.readline().split())

    lis = [ list(map(int,stdin.readline().split())) for i in range(n) ]

    one = set()
    for i in range(n):
        one.add(lis[i][0])

    A = None
    for i in range(m):

        a = list(map(int,stdin.readline().split()))
        if a[0] in one:
            A = a

    rev = {}
    a = A

    for i in range(len(a)):
        rev[a[i]] = i

    
    nlis = []
    for x in lis:

        nlis.append( [rev[x[0]]] + x )

    nlis.sort()

    for i in nlis:
        ANS.append(" ".join(map(str,i[1:])))

print ("\n".join(ANS))