SDE - 1

You are given two Singly Linked Lists of integers, which may have an intersection point.

Your task is to return the first intersection node. If there is no intersection, return NULL.

Example:-

The Linked Lists, where a1, a2, c1, c2, c3 is the first linked list and b1, b2, b3, c1, c2, c3 is the second linked list, merging at node c1.

You are given an array ‘arr’ consisting only of 0s , 1s, and 2s.

Sort the given array.

For Example:

For ‘arr’ = {1, 0, 0, 2, 1}.
‘Answer’ = {0, 0, 1, 1, 2}.
‘Answer’ should contain all 0s first, then all 1s and all 2s in the end.

You are given an array 'ARR' consisting of 'N' integers. You need to rearrange the array elements such that all negative numbers appear before all positive numbers.

Note:

The order of elements in the resulting array is not important.

Example:

Let the array be [1, 2, -3, 4, -4, -5]. On rearranging the array such that all negative numbers appear before all positive numbers we get the resulting array [-3, -5, -4, 2, 4, 1].

Aahad and Harshit always have fun by solving problems. Harshit took a sorted array consisting of distinct integers and rotated it clockwise by an unknown amount. For example, he took a sorted array = [1, 2, 3, 4, 5] and if he rotates it by 2, then the array becomes: [4, 5, 1, 2, 3].

After rotating a sorted array, Aahad needs to answer Q queries asked by Harshit, each of them is described by one integer Q[i]. which Harshit wanted him to search in the array. For each query, if he found it, he had to shout the index of the number, otherwise, he had to shout -1.

For each query, you have to complete the given method where 'key' denotes Q[i]. If the key exists in the array, return the index of the 'key', otherwise, return -1.

Note:

Can you solve each query in O(logN) ?

Design a Make-my-trip kind-of, Database design, provide a query to fetch data from the database.

Given an input string (STR), print all possible permutations of the input string.