Suppose we have a string s. We have to remove all duplicate characters that have already appeared before. The final string will have same ordering of characters like the actual one.We can solve this by using ordered dictionary to maintain the insertion order of the characters. The value will be ... Read More

Suppose we have a credit card number. We have to check whether the card number is valid or not. The card numbers have certain properties −It will start with 4, 5 and 6It will be 16 digits’ longNumbers must contain only digitsIt may have digits in four groups separated by ... Read More

Suppose we have a string s of size n. We have to find all rotated strings by rotating them 1 place, 2 places ... n places.So, if the input is like s = "hello", then the output will be ['elloh', 'llohe', 'lohel', 'ohell', 'hello']To solve this, we will follow these ... Read More

Suppose we have a number n. We have to find the sum of first n Fibonacci terms (Fibonacci sequence up to n terms). If the answer is too large then return result modulo 10^8 + 7.So, if the input is like n = 8, then the output will be 33 ... Read More

Suppose we have a list of elements called nums, and a value k. We have to find those elements which have occurred at least k number of times.So, if the input is like nums = [2, 5, 6, 2, 6, 1, 3, 6, 3, 8, 2, 5, 9, 3, 5, ... Read More

Suppose we have a list of rational numbers. We have to find their product using reduce function. The reduce() function applies a function with two arguments cumulatively on a list of objects from left to right.So, if the input is like fractions = [(5, 3), (2, 8), (6, 9), (5, ... Read More

Suppose we have an email address as string. We have to check whether this is valid or not based on the following conditions −The format must be username@company.domain formatUsername can only contain upper and lowercase letters, numbers, dashes and underscoresCompany name can only contain upper and lowercase letters and numbersDomain ... Read More

Suppose we have a number x and another number n. We have to find number of ways we can get x as sum of nth power of some unique numbers.So, if the input is like x = 100 n = 2, then the output will be 3 because possible solutions ... Read More

Suppose we have one alphanumeric string s. We have to sort it based on following conditionAll sorted lowercase letters will be placed before uppercase letters.All sorted uppercase letters will be placed before digits.All sorted odd digits will be placed before sorted even digits.So, if the input is like s = ... Read More

Suppose we have a 2d list containing information about athletes. This information is rank, age, height. Each row contains information for different athletes. We also have another number k. We have to sort the data based on kth attribute.So, if the input is likeRankageheight125190235180333185426175535180And k = 1.then the output will ... Read More