We need to take three-pointers, low, mid, high. We will use low and mid pointers at the start, and the high pointer will point at the end of the given array.If array [mid] =0, then swap array [mid] with array [low] and increment both pointers once.If array [mid] = 1, ... Read More

Take two-pointers, low, high. We will use low pointers at the start, and the high pointer will point at the end of the given array.If array [low] =0, then no swapping requiredIf array [low] = 1, then swapping is required. Decrement high pointer once.Time complexity − O(N)Example Live Demousing System; namespace ... Read More

Given an array and number k, the problem states that we have to rotate the array k times.If the given number is 3 then the array must be rotated 3 times.Create a function reverse which takes the array, start and end as a parameter.In the 1st step call reverse method ... Read More

HasPathsum takes 2 parameters one is the tree node and other is the sum value, initially we check whether the node is null or not, if the node is null then we return false. If the node is not null then we call HasPathSum recursive method, in each and every ... Read More

A tree is a binary search tree if it has all the left child lesser than the node elements and all the right child greater than the node elements. Initially we check whether the node has any value, if the node is null then we consider as valid binary search ... Read More

To invert a binary search tree, we call a method InvertABinarySearchTree which takes node as a parameter. If the node is null then return null, if the node is not null, we call the InvertABinarySearchTree recursively by passing the left and right child values. and assign the right child value ... Read More

In the recursive approach we to find a tree is symmetric or not we initially check whether the tree is null or not, if the tree is null then its symmetric, if the tree is not not null we call amethod issymmetricmirror .In isSymmetricMirror we get the value of the ... Read More

In the Iterative approach we have to create 2 Queues, one queue saves the left child and another queue saves the right child value. If the tree is empty, then it is symmetrical to the vertical axis going through its root node. Else, check if the value at the root ... Read More

CoinChangeBottomUpApproach takes 3 parameters as input n is the amount, coins array contains the total number of coins, t contains total number of coins. Declare a dynamic array which stores the previously calculated values. loop through the array and calculate the minimum coins required to calculate the amount. If the ... Read More

CoinChangeTopDownApproach takes 4 parameters, n is the amount, coins array contains the coins from which the amount needs to be calculated, t is the total number of coins, dp array will store all the pre calculated values. If amount is 0 then return 0. If the value is already calculated ... Read More