On a N x N grid of cells, each cell (x, y) with 0 <= x < N and 0 <= y < N has a lamp.
Initially, some number of lamps are on. lamps[i] tells us the location of the i-th lamp that is on. Each lamp that is on illuminates every square on its x-axis, y-axis, and both diagonals (similar to a Queen in chess).
For the i-th query queries[i] = (x, y), the answer to the query is 1 if the cell (x, y) is illuminated, else 0.
After each query (x, y) [in the order given by queries], we turn off any lamps that are at cell (x, y) or are adjacent 8-directionally (ie., share a corner or edge with cell (x, y).)
Return an array of answers. Each value answer[i] should be equal to the answer of the i-th query queries[i].
Example 1:
Input: N = 5, lamps = [[0,0],[4,4]], queries = [[1,1],[1,0]]
Output: [1,0]
Explanation:
Before performing the first query we have both lamps [0,0] and [4,4] on.
The grid representing which cells are lit looks like this, where [0,0] is the top left corner, and [4,4] is the bottom right corner:
1 1 1 1 1
1 1 0 0 1
1 0 1 0 1
1 0 0 1 1
1 1 1 1 1
Then the query at [1, 1] returns 1 because the cell is lit. After this query, the lamp at [0, 0] turns off, and the grid now looks like this:
1 0 0 0 1
0 1 0 0 1
0 0 1 0 1
0 0 0 1 1
1 1 1 1 1
Before performing the second query we have only the lamp [4,4] on. Now the query at [1,0] returns 0, because the cell is no longer lit.
分析
N 皇后 sodoku
此做法python TLE
from collections import Counter
class Solution:
def gridIllumination(self, N: int, lamps: List[List[int]], queries: List[List[int]]) -> List[int]:
lamps = set(list(map(tuple, lamps)))
h,v,l,r = Counter(),Counter(),Counter(),Counter()
res = []
for x,y in lamps:
h[x]+=1
v[y]+=1
l[x+y]+=1
r[x-y]+=1
for x,y in queries:
if (x,y) in lamps or h[x] or v[y] or l[x+y] or r[x-y]:
res.append(1)
else:
res.append(0)
for nx in range(x-1,x+2):
for ny in range(y-1,y+2):
if (nx,ny) in lamps:
lamps.remove((nx,ny))
h[nx] -= 1
if h[nx] == 0:
del h[nx]
v[ny] -= 1
if v[ny] == 0:
del v[ny]
l[nx+ny] -= 1
if l[nx+ny] == 0:
del l[nx+ny]
r[nx-ny] -= 1
if r[nx-ny] == 0:
del r[nx-ny]
return res