547. Number of Provinces

Medium

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There are n cities. Some of them are connected, while some are not. If city a is connected directly with city b, and city b is connected directly with city c, then city a is connected indirectly with city c.

A province is a group of directly or indirectly connected cities and no other cities outside of the group.

You are given an n x n matrix isConnected where isConnected[i][j] = 1 if the ith city and the jth city are directly connected, and isConnected[i][j] = 0 otherwise.

Return the total number of provinces.

Example 1:

Input: isConnected = [[1,1,0],[1,1,0],[0,0,1]]
Output: 2

Example 2:

Input: isConnected = [[1,0,0],[0,1,0],[0,0,1]]
Output: 3

Constraints:

• 1 <= n <= 200

• n == isConnected.length

• n == isConnected[i].length

• isConnected[i][j] is 1 or 0.

• isConnected[i][i] == 1

• isConnected[i][j] == isConnected[j][i] <--- Remember this line while solving

class Solution:
    def findCircleNum(self, isConnected: List[List[int]]) -> int:
        visited = [False]*len(isConnected)
        result = []
        for row in range(len(isConnected)):
            for col in range(len(isConnected[0])):
                if isConnected[row][col] == 1 and not visited[col]:
                    result.append(self.findConnectedNodes(visited, isConnected, col))
        return len(result)
    # Simply Traversing Adjency Matrix
    def findConnectedNodes(self, visited, isConnected, node, connectedNodeList=[]):
        visited[node] = True
        for col in range(len(isConnected[0])):
            if isConnected[node][col] == 1 and not visited[col]:
                connectedNodeList.append(self.findConnectedNodes(visited, isConnected, col))
        return connectedNodeList