题目链接
2670. 找出不同元素数目差数组 - 力扣（LeetCode）
解题思路
暴力破解
class Solution:
def distinctDifferenceArray(self, nums: List[int]) -> List[int]:
mapbefore = [1] * len(nums)
tmp = [nums[0]]
for i in range(1,len(nums)):
if nums[i] not in tmp:
tmp.append(nums[i])
mapbefore[i] = mapbefore[i - 1] + 1
else:
mapbefore[i] = mapbefore[i - 1]
print(mapbefore)
mapafter = [0] * len(nums)
tmp = []
for i in range(len(nums) - 2, -1, -1):
if nums[i + 1] not in tmp:
tmp.append(nums[i + 1])
mapafter[i] = mapafter[i + 1] + 1
else:
mapafter[i] = mapafter[i + 1]
print(mapafter)
result = []
for i in range(0,len(nums)):
result.append(mapbefore[i]-mapafter[i])
return result
使用set（）
class Solution:
def distinctDifferenceArray(self, nums: List[int]) -> List[int]:
st = set()
sufCnt = [0] * (len(nums) + 1)
for i in range(len(nums) - 1, 0, -1):
st.add(nums[i])
sufCnt[i] = len(st)
res = []
st.clear()
for i in range(len(nums)):
st.add(nums[i])
res.append(len(st) - sufCnt[i + 1])
return res