We are given an array containing integer elements. The goal is to find unique pairs of elements of array such that pairs of type (arr[i],arr[j]) have indexes such that iLet us understand with examplesInput − arr[] = {1,2,3};Output − Count of unique pairs (arr[i], arr[j]) such that i < j are − 3Explanation − As all elements are unique. Pairs would be −(1,2) - ( arr[0],arr[1] ) 0

We are given an array arr[] containing integers only. The goal is to find the number of subsequences of arr[] such that they have maximum number distinct elements. If the array is [ 4, 1, 2, 3, 4 ] then two subsequences will be [ 4, 1, 2, 3 ] and [ 1, 2, 3, 4 ].Let us understand with examplesInput − arr[]= { 1, 3, 5, 4, 2, 3, 1 }Output − Count of subsequences having maximum distinct elements are − 4Explanation − The maximum distinct elements are 1, 2, 3, 4 and 5. Count is 5. Subsequences will ... Read More

We are given a positive integer N. The goal is to find the number of operations required to reduce N to 0. Operation applied is N=N-P where P is the smallest prime divisor of P.Let us understand with examplesInput − N=17Output − Count of operations of the given type required to reduce N to 0 are − 1Explanation − The smallest prime divisor of 17 is 17 itself. So the operation is applied only once 17-17=0.Input − N=20Output− Count of operations of the given type required to reduce N to 0 are − 10Explanation − The smallest prime divisor of ... Read More

We are given two binary search trees as input and a variable x. The goal is to find pairs of nodes from each tree such that the sum of value of nodes is equal to x. Take node 1 from BST_1 and node 2 from BST_2 and add data part of both. If sum=x. Increment count.Let us understand with examples.Input Output − Count of pairs from two BSTs whose sum is equal to a given value x are − 1Explanation − The pair is (8, 6)Input Output −Count of pairs from two BSTs whose sum is equal to a given value x ... Read More

We are given two arrays containing positive numbers and a value K. The goal is to find unique pairs of elements of arrays such that pairs of type (A, B) has A%B=K or B%A=K and A belongs to the first array and B belongs to the second array.Let us understand with examplesInput − arr_1[] = {1, 2, 5, 3, 4}; arr_2[] = {7, 1, 3}; k=2Output − Count of pairs from two arrays whose modulo operation yields K are − 2Explanation − The pairs are (5, 7) - (arr_1[2], arr_2[1]) 7%5=2 and (5, 3) - (arr_1[2], arr_2[2]) 5%3=2Input − arr_1[] ... Read More

We are given two arrays containing positive numbers and a value x. The goal is to find pairs of elements of arrays such that pairs of type (A, B) has A+B=x and A belongs to the first array and B belongs to the second array.Let us understand with examplesInput − arr_1[] = {1, 2, 5, 3, 4}; arr_2[] = {7, 0, 1, 3}; x=6Output −Count of pairs from two sorted arrays whose sum is equal to a given value x are − 2Explanation − The pairs are (5, 1) - (arr_1[2], arr_2[2]) and (3, 3) - (arr_1[3], arr_2[3])Input − arr_1[] ... Read More

We are given an array of positive integers. The goal is to find the count of distinct pairs of elements of an array that have at-least one prime member. If the array is [1, 2, 3, 4] then pairs would be (1, 2), (1, 3), (2, 3), (2, 4) and (3, 4).Let us understand with examplesInput − arr[] = { 1, 2, 4, 8, 10 };Output − Count of pairs in an array such that at least one element is prime are − 4Explanation − The only prime element is 2 and pairing it with all others will give − ... Read More

We are given an array of positive integers. The goal is to find the count of pairs of elements of arr[] such that condition LCM( arr[i], arr[j] ) > minimum of ( arr[i], arr[j] ). That is, the lowest common multiple of elements in a pair is greater than the minimum of both.Note − pair ( arr[i], arr[j] ) is the same as ( arr[j], arr[i] ). Don’t count it twice.Let us understand with examples.Input − arr[] = [ 1, 5, 4, 2 ]Output − Count of pairs in an array such that LCM(arr[i], arr[j]) > min(arr[i], arr[j]) are − ... Read More

We are given an array of numbers. The goal is to find the pair of elements of array such that they hold the conditionIf (i*arr[i] > j*arr[j]) then (arr[i], arr[j]) is a valid pair.If the array is [ 5, 4, 3, 2, 1 ] then pairs will be [3, 1] and [2, 1].Let us understand with examples.Input − arr[] = [ 1, 5, 4, 1, 2, 8, 3 ]Output − Count of pairs in an array that hold i*arr[i] > j*arr[j] are − 3Explanation − Pairs are (5, 1), (4, 1), (8, 3)Input − arr[] = [ -1, -2, 3, ... Read More

We have a sequence generator that starts with 1. At each step 0 becomes 10 and 1 becomes 01. So following changes will occur at consecutive steps −Step 1 − 01Step 2 − 1001Step 3 − 01101001 ……The goal is to find the number of pairs of consecutive 0’s for a given number of steps.If input step is 1 pair of 0’s - 0, input step is 2 pair of 0’s - 1, input step is 3 pair of 0’s 1Step 4 − 1001011001101001Step 5 − 01101001100101101001011001101001We can observe that sequence is increasing in powers of 2 and repeats itself ... Read More