Number of Students Unable to Eat Lunch

Number of Subarrays That Match a Pattern II

Number of Substrings With Fixed Ratio

Number of Substrings With Only 1s

Number of Times a Driver Was a Passenger

Number of Transactions per Visit

Number of Unequal Triplets in Array

Number of Unique Categories

Number of Unique Flavors After Sharing K Candies

Number of Valid Subarrays