province.rb

# @param {Integer[][]} is_connected
# @return {Integer}
def find_circle_num(is_connected)
    visited = Array.new(is_connected.length, 0)
    count = 0
    
    for i in 0...is_connected.length
        if visited[i] == 0 && visited.uniq != [1]
        
            dfs(i, is_connected, visited, [i]) 
            count += 1
        end
    end
    count
end

def dfs(i, is_connected, visited, stack = [])
    
    return if visited.uniq == 1
    return if i.nil?

    for j in 0...is_connected.length
        stack.push(j) if is_connected[i][j] == 1 && visited[j] == 0
    end


    while stack.length > 0
        current = stack.shift
        visited[current] = 1


        dfs(stack[0], is_connected, visited, stack)
        
    end    
end