Problem
Given an array of integers and an integer k, you need to find the total number of continuous subarrays whose sum equals to k.
Example 1:
Input:nums = [1,1,1], k = 2
Output: 2
Note:
The length of the array is in range [1, 20,000].
The range of numbers in the array is [-1000, 1000] and the range of the integer k is [-1e7, 1e7].
Solution
class Solution:
def subArraySum(self, nums, k):
h = {0: 1}
s = 0
ans = 0
for i in nums:
s += i
ans += h.get(s-k, 0)
h[s] = h.get(s, 0) + 1
return ans