문제 : https://www.acmicpc.net/problem/1012 

▶ 코드 ( 재귀 ver. )

import sys
sys.setrecursionlimit(10**8) # 10^8 까지 늘림.


T = int(input())

for _ in range(T):
    m, n, k = map(int, input().split())
    myMap = [[0]*m for _ in range(n)]
    for _ in range(k):
        a, b = map(int, input().split())
        myMap[b][a] = 1

    #print(myMap)
    visited = [[0]*m for _ in range(n)]

    dx = [1,-1,0,0]
    dy = [0,0,1,-1]
        

    def isInGraph(r, l): # r: 세로, l: 가로
        if r < 0 or r >= n or l < 0 or l >= m:
            return False
        return True
        
    def bfs(r, l):
        visited[r][l] = 1

        tx = 0
        ty = 0
        for i in range(4):
            tx = r + dx[i]
            ty = l + dy[i]

            if isInGraph(tx, ty):
                if visited[tx][ty] == 0 and myMap[tx][ty] == myMap[r][l]:
                    bfs(tx, ty)

    ans = 0
    for i in range(n): # 세로길이
        for j in range(m): # 가로길이 
            if visited[i][j] == 0 and myMap[i][j] != 0:
                bfs(i, j)
                ans += 1
    print(ans)


# pypy로 제출하면 메모리초과. python3로 제출해야됨 

※ python3로 채점해야 메모리초과 X