560. Subarray Sum Equals K - cocoder39/coco39_LC GitHub Wiki
class Solution:
def subarraySum(self, nums: List[int], k: int) -> int:
total = 0
res = 0
count = collections.defaultdict(int)
count[0] = 1
for num in nums:
total += num
if (total - k) in count:
res += count[total-k]
count[total] += 1
return res