class isLandsInGrid:
def __init__(self , n , m):
self.n = n
self.m = m
self.uf = UF(n*m , None) #we will use a linear representation for indices (i,j)=>i*n+j
def numIslandsAfterAddingLands(self , positions):
dirs = [(-1 , 0) , (1 , 0) , (0 , -1) , (0 , 1)]
result = []
for pos in positions:
linearPos = pos[0]*self.n + pos[1]
self.uf.ids[linearPos] = linearPos
self.uf.count += 1
for d in dirs:
x = pos[1] + d[1]
y = pos[0] + d[0]
neighbor = linearPos + d[0]*self.n + d[1]
if x < 0 or x >= self.n or y < 0 or y >= self.m or self.uf.ids[neighbor] is None:
continue #in this case the neighbor is either not defined or it is not land
if self.uf.ids[neighbor] != self.uf.ids[linearPos]:
self.uf.union(linearPos , neighbor)
result.append(self.uf.count)
return result
def __init__(self , n , m):
self.n = n
self.m = m
self.uf = UF(n*m , None) #we will use a linear representation for indices (i,j)=>i*n+j
