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
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.
Solution
/**
* @param {number[]} nums
* @return {number}
*/
var zeroFilledSubarray = function(nums) {
//Declare Counter and static 0 counter
let count = 0;
let zeroCount = 0;
//Loop through nums
for (let i = 0; i < nums.length; i++) {
//If the current number is 0, increment the zero counter
if (nums[i] === 0) {
zeroCount++;
} else {
//If the current number is not 0, add the number of subarrays to the counter
count += (zeroCount * (zeroCount + 1)) / 2;
zeroCount = 0;
}
}
//Add the number of subarrays to the counter
count += (zeroCount * (zeroCount + 1)) / 2;
return count;
};