Data Analyst

Ninja has a robot that can move in an infinite number line. The robot starts at position 0, with speed = +1. The robot moves automatically according to the sequence of instructions “A” (Accelerate) and “R” (Reverse).

When robot get an instruction "A", the robot does the following: position += speed, speed *= 2.

When the robot gets an instruction “R”, the robot does the following: if its speed is positive then speed = -1, otherwise speed = +1. The position of the robot will remain the same.

For example, after commands "AAARA", the robot goes to positions 0->1->3->7->7->6, and robot speed goes to 1->2->4->8->-1->-2.

You are given a positive integer ‘TARGET’, and your task is to find and return the length of the shortest sequence of instruction to reach position equals ‘TARGET’.

Note :

The position of the robot can be negative.

You are given an array arr consisting of ‘N’ integers. Your task is to find the largest number, ‘K’, such that both the values ‘K’ and -‘K’ are present in the given array 'arr'. If no such number exists, then return '-1'.

For example:

Consider ‘arr’ = [1,2,-2,-1], the largest value of ‘K’ is 2, since a negative of 2 is also present in the array. Hence, the answer is 2.

You are given a 9x9 sudoku. Your task is to solve sudoku and return the solution.

A sudoku is a puzzle in which players insert the numbers one to nine into a grid consisting of nine squares subdivided into a further nine smaller squares in such a way that every number appears once in each horizontal line, vertical line, and square.

For example: Consider following sudoku:

To solve it you have to fill blank spaces by numbers from 1 to 9 subject to constraints:

Any number should not occur more than once per row.

Any number should not occur more than once per column.

Any number should not occur more than once per block of 3x3(here, each block is distinguished by bold borders).

It will be solved as: