Given an n × n adjacency matrix where isConnected[i][j] = 1 means cities i and j are directly connected, find the number of provinces.
A province is a group of cities connected directly or indirectly.
With isConnected = [[1,1,0],[1,1,0],[0,0,1]]:
- Cities 0 and 1 are connected (isConnected[0][1] = 1).
- City 2 is isolated.
- 2 provinces: {0,1} and {2}.
With isConnected = [[1,0,0],[0,1,0],[0,0,1]]:
- No connections between cities.
- 3 provinces: each city is its own province.
Constraints: .