_930. Binary Subarrays With Sum.md

930. Binary Subarrays With Sum

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First completed : June 21, 2024

Last updated : June 21, 2024

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Related Topics : Array, Hash Table, Sliding Window, Prefix Sum

Acceptance Rate : 62.625 %

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Solutions

• m930.py

Python

m930.py

# Extremly similar to m1248

class Solution:
    def numSubarraysWithSum(self, nums: List[int], goal: int) -> int:
        output = 0
        runningSum = 0

        prefixes = defaultdict(int)
        prefixes[0] = 1

        for num in nums :
            runningSum += num

            difference = runningSum - goal

            if difference in prefixes :
                output += prefixes[difference]
            
            prefixes[runningSum] += 1

        return output