Warmup:
- Lonely Interger There are N integers in an array A. All but one integer occur in pairs. Your task is to find out the number that occurs only once. link
- Flipping Bits You will be given a list of 32 bits unsigned integers. You are required to output the list of the unsigned integers you get by flipping bits in its binary representation (i.e. unset bits must be set, and set bits must be unset). link
- Utopian Tree The Utopian Tree goes through 2 cycles of growth every year. The first growth cycle occurs during the spring, when it doubles in height. The second growth cycle occurs during the summer, when its height increases by 1 meter. Now, a new Utopian Tree sapling is planted at the onset of spring. Its height is 1 meter. Can you find the height of the tree after N growth cycles? link
- Maximizing XOR Given two integers, L and R, find the maximal values of A xor B, where A and B satisfies the following condition: L <= A<= <= B <= R link
- Alernating Characters Shashank likes strings in which consecutive characters are different. For example, he likes ABABA, while he doesn’t like ABAA. Given a string containing characters A and B only, he wants to change it into a string he likes. To do this, he is allowed to delete the characters in the string.Your task is to find the minimum number of required deletions. link
- The Love-Letter Mystery James found a love letter his friend Harry has written for his girlfriend. James is a prankster, so he decides to meddle with the letter. He changes all the words in the letter into palindromes. link
- Game Of Thrones Dothraki are planning an attack to usurp King Robert from his kingdom. King Robert learns of this conspiracy from Raven and plans to lock the single door through which an enemy can enter his kingdom. But, to lock the door he needs a key that is an anagram of a certain palindrome string. link
- ACM ICPC Team You are given a list of N people who are attending ACM-ICPC World Finals. Each of them are either well versed in a topic or they are not. Find out the maximum number of topics a 2-person team can know. And also find out how many teams can know that maximum number of topics. link
- Filling Jars Animesh has N empty candy jars, numbered from 1 to N, with infinite capacity. He performs M operations. Each operation is described by 3 integers a, b and k. Here, a and b are indices of the jars, and k is the number of candies to be added inside each jar whose index lies betweena and b (both inclusive). Can you tell the average number of candies after M operations? link
- Chocolate Feast Little Bob loves chocolates, and goes to a store with $N in his pocket. The price of each chocolate is $C. The store offers a discount: for every M wrappers he gives to the store, he gets one chocolate for free. How many chocolates does Bob get to eat? link
- Sherlock and Squares Watson gives two integers A & B to Sherlock and asks if he can count the number of square integers between A and B (both inclusive).A square integer is an integer which is the square of any integer. For example, 1, 4, 9, 16 are some of the square integers as they are squares of 1, 2, 3, 4 respectively. link
- Halloween Party Alex is attending a Halloween party with his girlfriend Silvia. At the party, Silvia spots the corner of an infinite chocolate bar. If the chocolate can be served as only 1 x 1 sized pieces and Alex can cut the chocolate bar exactly K times, what is the maximum number of chocolate pieces Alex can cut and give Silvia? link
- Manasa and Stones Manasa is out on a hike with friends. She finds a trail of stones with numbers on them. She starts following the trail and notices that two consecutive stones have a difference of either aor b. Legend has it that there is a treasure trove at the end of the trail and if Manasa can guess the value of the last stone, the treasure would be hers. Given that the number on the first stone was 0, find all the possible values for the number on the last stone. link
- Sherlock and GCD Sherlock is stuck while solving a problem: Given an array A={a1,a2,..aN}, he wants to know if there exists a subset, B={ai1,ai2,…aik} where 1<=i1 < i2 < ... < ik <= N ... link
- Find Digits You are given an integer N. Find the digits in this number that exactly divide N (division that leaves 0 as remainder) and display their count. For N=24, there are 2 digits (2 & 4). Both of these digits exactly divide 24. So our answer is 2. link
- AngryProfessor The professor is conducting a course on Discrete Mathematics to a class of N students. He is angry at the lack of their discipline, and he decides to cancel the class if there are less than K students present after the class starts. Given the arrival time of each student, your task is to find out if the class gets cancelled or not. link
- Two Strings You are given two strings, A and B. Find if there is a substring that appears in both A and B. link
- Is Fibo You are given an integer, N. Write a program to determine if N is an element of the Fibonacci sequence. link
- Taum and B’day Taum is planning to celebrate the birthday of his friend Diksha. There are two types of gifts that Diksha wants from Taum: one is black and the other is white. To make her happy, Taum has to buy B number of black gifts and W number of white gifts. link
- Cavity Map You are given a square map of size n×n. Each cell of the map has a value denoting its depth. We will call a cell of the map a cavity if and only if this cell is not on the border of the map and each cell adjacent to it has strictly smaller depth. Two cells are adjacent if they have a common side. link
- Cut the sticks You are given N sticks, where each stick has the length of a positive integer. A cut operation is performed on the sticks such that all of them are reduced by the length of the smallest stick. link
- Service Lane Calvin is driving his favorite vehicle on the 101 freeway. He notices that the check engine light of his vehicle is on, and he wants to service it immediately to avoid any risks. Luckily, a service lane runs parallel to the highway. The length of the highway and the service lane is N units. The service lane consists of N segments of equal length and different width. link
- Max Min’ / ‘Angry Children Given a list of N integers, your task is to select K integers from the list such that its unfairness is minimized. link
Arrays and Sorting:
- Closest Numbers Given a list of unsorted integers, A={a1,a2,…,aN}, can you find the pair of elements that have the smallest absolute difference between them? If there are multiple pairs, find them all. link
- Sherlock and Watson John Watson performs an operation called Right Circular Rotation on an integer array [a0, a1, … an-1]. Right Circular Rotation transforms the array from [a0, a1, … aN-1] to [aN-1, a0,… aN-2].He performs the operation K times and tests Sherlock’s ability to identify the element at a particular position in the array. He asks Q queries. Each query consists of one integer, idx, for which you have to print the element at index idx in in the rotated array, i.e., aidx. link
- Sherlock and Pairs Sherlock is given an array of N integers A0, A1...AN-1 by Watson. Now Watson asks Sherlock how many different pairs of indices i and j exist such that i is not equal to j but Ai is equal to Aj.That is, Sherlock has to count total number of pairs of indices (i, j) where Ai = Aj AND i != j. link
Search:
- Ice Cream Parlor Sunny and Johnny together have M dollars they want to spend on ice cream. The parlor offers N flavors, and they want to choose two flavors so that they end up spending the whole amount. You are given the cost of these flavors. The cost of the ith flavor is denoted by ci. You have to display the indices of the two flavors whose sum is M. link
- Encryption An English text needs to be encrypted using the following encryption scheme. First, the spaces are removed from the text. Let L be the length of this text. link
- Count Luck Hermione Granger is lost in the Forbidden Forest while collecting some herbs for a magical potion. The forest is magical and has only one exit point, which magically transports her back to the Hogwarts School of Witchcraft and Wizardry. link
- Sherlock and Array Watson gives Sherlock an array A of length N. Then he asks him to determine if there exists an element in the array such that the sum of the elements on its left is equal to the sum of the elements on its right. If there are no elements to the left/right, then the sum is considered to be zero. Formally, find an i, such that, A1+A2…Ai-1 =Ai+1+Ai+2…AN. link
- Circle City Roy lives in a city that is circular in shape on a 2D plane that has radius r. The city center is located at origin (0,0) and it has suburbs lying on the lattice points (points with integer coordinates). The city Police Department Headquarters can only protect those suburbs which are located strictly inside the city. The suburbs located on the border of the city are still unprotected. So the police department decides to build at most k additional police stations at some suburbs. Each of these police stations can protect the suburb it is located in. link
- Missing Numbers Numeros, the Artist, had two lists A and B, such that B was a permutation of A. Numeros was very proud of these lists. Unfortunately, while transporting them from one exhibition to another, some numbers from A got left out. Can you find the numbers missing? link
- The Grid Search Given a 2D array of digits, try to find the location of a given 2D pattern of digits. link
- Number List Shashank loves to play with arrays a lot. Today, he has an array A consisting of N positive integers. At first, Shashank listed all the subarrays of his array A on a paper and later replaced all the subarrays on the paper with the maximum element present in the respective subarray. link
String:
- Funny String Suppose you have a string S which has length N and is indexed from 0 to N−1. String R is the reverse of the string S. The string S is funny if the condition |Si−Si−1|=|Ri−Ri−1| is true for every i from 1 to N−1. link
- Pangrams Roy wanted to increase his typing speed for programming contests. So, his friend advised him to type the sentence “The quick brown fox jumps over the lazy dog” repeatedly, because it is a pangram. (Pangrams are sentences constructed by using every letter of the alphabet at least once.) link
- Alternating Characters Shashank likes strings in which consecutive characters are different. For example, he likes ABABA, while he doesn’t like ABAA. Given a string containing characters A and B only, he wants to change it into a string he likes. To do this, he is allowed to delete the characters in the string. Your task is to find the minimum number of required deletions. link
- Gemstones John has discovered various rocks. Each rock is composed of various elements, and each element is represented by a lower-case Latin letter from ‘a’ to ‘z’. An element can be present multiple times in a rock. An element is called a gem-element if it occurs at least once in each of the rocks. Given the list of N rocks with their compositions, display the number of gem-elements that exist in those rocks. link
- Make it Anagram Alice recently started learning about cryptography and found that anagrams are very useful. Two strings are anagrams of each other if they have same character set. For example strings"bacdc" and "dcbac" are anagrams, while strings "bacdc" and "dcbad" are not. Alice decides on an encryption scheme involving 2 large strings where encryption is dependent on the minimum number of character deletions required to make the two strings anagrams. She need your help in finding out this number. Given two strings (they can be of same or different length) help her in finding out the minimum number of character deletions required to make two strings anagrams. Any characters can be deleted from any of the strings. link
- Anagram Sid is obsessed with reading short stories. Being a CS student, he is doing some interesting frequency analysis with the books. He chooses strings S1 and S2 in such a way that |len(S1)−len(S2)| <= 1 link
Combinatorics:
- Handshake At the annual meeting of Board of Directors of Acme Inc, every one starts shaking hands with everyone else in the room. Given the fact that any two persons shake hand exactly once, Can you tell the total count of handshakes? link
Machine Learning: