Suppose an array A of 0s and 1s is given, we have to find how many non-empty subarrays have sum S? So if the input is like [1, 0, 1, 0, 1], and S = 2, then the result will be 4, as the subarrays are [1, 0, 1, 0, 1], [1, 0, 1, 0, 1], [1, 0, 1, 0, 1], [1, 0, 1, 0, 1].To solve this, we will follow these steps −Define a method called atMost(), this will take array A and integer xif x < 0, then return 0, set j := 0 and set ret := ... Read More

Suppose a string of '0's and '1's is given. That string will be monotonic increasing if it consists of some number of '0's (possibly 0), followed by some number of '1's (also possibly 0.). We have a string S of '0's and '1's, and we may flip any '0' to a '1' or a '1' to a '0'. Find the minimum number of flips to make S monotone increasing. So if the input is like “010110”, then the output will be 2. By flipping we can get “011111” or “000111”.To solve this, we will follow these steps −n := size ... Read More

Suppose we have an array A, we have to partition it into two subarrays left and right such that −Every element in left subarray is less than or equal to every element in right subarray.left and right subarrays are non-empty.left subarray has the smallest possible size.We have to find the length of left after such a partitioning. It is guaranteed that such a partitioning exists.So if the input is like [5, 0, 3, 8, 6], then the output will be 3, as left array will be [5, 0, 3] and right subarray will be [8, 6].To solve this, we will ... Read More

Suppose we have an array of integers; we have to sort them in ascending order. So if the array is like [5, 2, 3, 1], then the result will be [1, 2, 3, 5]To solve this, we will follow these steps −Make one method called partition, this will take array, low and highset pivot := lowfor i in range low to high – 1if nums[i] < nums[high], then swap(nums[i] and nums[pivot]), increase pivot by 1swap nums[pivot] and nums[high]Define a method called sortArr(), this will take array, low and highif low >= high, then returnpartitionIndex := partition(nums, low, high)sortArr(nums, low, partitionIndex ... Read More

Suppose in an election, the i-th vote was cast for persons[i] at time times[i]. Now, we have to implement the following query function: TopVotedCandidate.q(int t) this will find the number of the person that was leading the election at time t. Votes cast at time t will count towards our query. If there is a tie, the most recent vote (among tied candidates) wins.So if we initialize this with TopVotedCandidate([0, 1, 1, 0, 0, 1, 0], [0, 5, 10, 15, 20, 25, 30]), then call q() like: q(3), q(12), q(25), q(15), q(24), q(8), then the result will be [0, 1, ... Read More

Suppose we have an array A of integers, for each integer A[i] we have to choose either x = -K or x = K, and add x to A[i] (only once). So after this process, we have some array B. We have to find the smallest possible difference between the maximum value of B and the minimum value of B. So if the input is A = [0, 10], K = 2, then the output will be 6, as B = [2, 8].To solve this, we will follow these steps −set ret := 0, n := size of array Asort ... Read More

Suppose we have to create an iterator that iterates through a run-length encoded sequence. Here the iterator is initialized by calling RLEIterator(int[] A), where A is a run-length encoding of a sequence. So we can say that for all even i, A[i] tells us the number of times that the non-negative integer value A[i+1] is repeated in the sequence. Here iterator supports one function −next(int n): This function exhausts the next n elements (n >= 1) and returns the last element exhausted in this way. So if there is no element left to exhaust, next returns -1 instead.Suppose we start ... Read More

Suppose we have an array A of non-negative integers. For every (contiguous) subarray say B = [A[i], A[i+1], ..., A[j]] (with i

Suppose we have a set of N people (they are numbered 1, 2, ..., N), we would like to split everyone into two subgroups of any size. Now each person may dislike some other people, and they should not go into the same group. So, if dislikes[i] = [a, b], it indicates that it is not allowed to put the people numbered a and b into the same group. We have to find if it is possible to split everyone into two groups in this way.So if the input is like N = 4 and dislike = [[1, 2], [1, ... Read More

Suppose we have a 2 dimensional grid with R rows and C columns, we start from (r0, c0) facing east. Here, the north-west corner of the grid is at the first row and column, and the south-east corner of the grid is at the last row and column. We will walk in a clockwise spiral shape to visit every position in this grid. When we are at the outside the boundary of the grid, we continue our walk outside the grid (but may return to the grid boundary later.). We have to find a list of coordinates representing the positions ... Read More