Crack the Coding Interview

Write a program to find the minimum number of operations required to convert string X to string Y. You have the following three operations permitted on a string: 1) Insert a character 2) Delete a character 3) Replace a character. The edit distance between two strings is the minimum number of operations (insertions, deletions, or substitutions of characters) required to transform one string into the other.

The flood fill problem is a way to fill a region of connected pixels with a new colour, starting from a given pixel in an image. You are given an image represented by an m x n grid of integers, where the image[i] represents the pixel value at position (i, j). You are also given the coordinates of a starting pixel (x, y) and a new colour to use for the flood fill operation.

The key idea behind using a stack is that it allows for easy access to the most recently added element and easy removal of that element, which can be useful in situations where you need to keep track of a history of actions or reverse actions. So based on various use cases, there are several applications of the stack in coding problem-solving and computer programming.

The stack data structure is a type of collection that follows the Last In, First Out (LIFO) principle, meaning that the last item added to the stack will be the first one to be removed.Stack is a linear data structure that supports two primary operations: push and pop. When we add an element to the top, it is called a push operation. When we remove an element from the top, it is called a pop operation.

Write a program to count the number of possible triangles that can be formed with three elements from a given unsorted array of positive integers. The three elements, representing the lengths of the sides of a triangle, must satisfy the triangle inequality: the sum of any two sides must be greater than the third side.

Write a program that returns a fixed point in the given sorted array of distinct integers. A fixed point is an index i such that X[i] = i. If a fixed point exists, the program should return the index of the fixed point. If no fixed point is found, the program should return -1. Note that the integers in the array can be both positive and negative.