Question

2348. Number of Zero-Filled Subarrays

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Description

Given an integer array nums, return _the number of subarrays filled with _0.

A subarray is a contiguous non-empty sequence of elements within an array.

 

Example 1:

Input: nums = [1,3,0,0,2,0,0,4]
Output: 6
Explanation: 
There are 4 occurrences of [0] as a subarray.
There are 2 occurrences of [0,0] as a subarray.
There is no occurrence of a subarray with a size more than 2 filled with 0. Therefore, we return 6.

Example 2:

Input: nums = [0,0,0,2,0,0]
Output: 9
Explanation:
There are 5 occurrences of [0] as a subarray.
There are 3 occurrences of [0,0] as a subarray.
There is 1 occurrence of [0,0,0] as a subarray.
There is no occurrence of a subarray with a size more than 3 filled with 0. Therefore, we return 9.

Example 3:

Input: nums = [2,10,2019]
Output: 0
Explanation: There is no subarray filled with 0. Therefore, we return 0.

 

Constraints:

• 1 <= nums.length <= 105
• -109 <= nums[i] <= 109

Solutions

Solution 1

class Solution:
  def zeroFilledSubarray(self, nums: List[int]) -> int:
    ans = cnt = 0
    for v in nums:
      cnt = 0 if v else cnt + 1
      ans += cnt
    return ans

class Solution {
  public long zeroFilledSubarray(int[] nums) {
    long ans = 0;
    int cnt = 0;
    for (int v : nums) {
      cnt = v != 0 ? 0 : cnt + 1;
      ans += cnt;
    }
    return ans;
  }
}

class Solution {
public:
  long long zeroFilledSubarray(vector<int>& nums) {
    long long ans = 0;
    int cnt = 0;
    for (int& v : nums) {
      cnt = v ? 0 : cnt + 1;
      ans += cnt;
    }
    return ans;
  }
};

func zeroFilledSubarray(nums []int) (ans int64) {
  cnt := 0
  for _, v := range nums {
    if v != 0 {
      cnt = 0
    } else {
      cnt++
    }
    ans += int64(cnt)
  }
  return
}

function zeroFilledSubarray(nums: number[]): number {
  let ans = 0;
  let cnt = 0;
  for (const v of nums) {
    cnt = v ? 0 : cnt + 1;
    ans += cnt;
  }
  return ans;
}