Suppose we have a matrix mat[][]. It has character Z and P. The Z is the zombie and P is the plant. And another character * is a bare land. A zombie can attack the plant, when plant is adjacent to zombie. We have to find number of plants, that ... Read More

Suppose we have a string; we have to find first character that is repeated. So is the string is “Hello Friends”, the first repeated character will be l. As there are two l’s one after another.To solve this, we will use the hashing technique. Create one hash table, scan each ... Read More

Suppose we have a number n. We have to find the product of prime numbers between 1 to n. So if n = 7, then output will be 210, as 2 * 3 * 5 * 7 = 210.We will use the Sieve of Eratosthenes method to find all primes. ... Read More

Suppose we have an array A with n integers. We have to find one element K such that K is prime, and A[i] mod K is maximum for all valid i among all possible values of K. If no such numbers are found, then return -1. For example, if A ... Read More

Suppose we have three integers, a, b and x. The task is to get the multiple of x, which is closest to ab. So if a = 5, b = 4 and x = 3, then output will be 624. As 54 = 625, and 624 is the multiple of ... Read More

Suppose we have a number n, and we have to find the permutation of this number, that is divisible by 3, but not divisible by 6. If no such value can be made, then return -1. For example, if n is 336, then the output can be 363.As we know ... Read More

Suppose we have two integers N and K, and we have to find the permutation P of first N natural numbers such that there are exactly K elements which satisfies the condition GCD(P[i], i) > 1 for all 1

Suppose we have one matrix or order NxN. We have to find a pair of elements which forms maximum difference from any column of the matrix. So if the matrix is like −123535967So output will be 8. As the pair is (1, 9) from column 0.The idea is simple, we ... Read More

Suppose we have an array that represents elements of geometric progression in order. One element is missing. We have to find the missing element. So if arr = [1, 3, 27, 81], output is 9, as 9 is missing.Using binary search, we can solve this problem. We will go to ... Read More

Suppose we have an array that represents elements of arithmetic progression in order. One element is missing. We have to find the missing element. So if arr = [2, 4, 8, 10, 12, 14], output is 6, as 6 is missing.Using binary search, we can solve this problem. We will ... Read More