Friend Circles

LeetCode 547

class Solution:
    def findCircleNum(self, M):
        """
        :type M: List[List[int]]
        :rtype: int
        """
        """
        [[1,0,0,1],
         [0,1,1,0],
         [0,1,1,1],
         [1,0,1,1]]
        """
        visited = set()
        count = 0
        for i in range(len(M)):
            if i not in visited:
                self.dfs(M, visited, i)
                print(visited)
                count += 1
        return count
        
    def dfs (self, M, visited, i):
        for k, v in enumerate(M[i]):
            if v==1 and k not in visited:
                visited.add(k)
                self.dfs(M, visited, k)