Count Beautiful Splits in an Array
You are given an array nums.
A split of an array nums is beautiful if:
- The array
numsis split into three subarrays:nums1,nums2, andnums3, such thatnumscan be formed by concatenatingnums1,nums2, andnums3in that order. - The subarray
nums1is a prefix ofnums2ORnums2is a prefix ofnums3.
Return the number of ways you can make this split.
Example 1
Input
nums = [1,1,2,1]Output
2The beautiful splits are with nums1 = [1], nums2 = [1,2], nums3 = [1], and with nums1 = [1], nums2 = [1], nums3 = [2,1].
Example 2
Input
nums = [1,2,3,4]Output
0There are 0 beautiful splits.
Constraints
- 1 <= nums.length <= 5000
- 0 <= nums[i] <= 50