You need to find the minimum number of refueling stops that a car needs to make to cover a distance, target. For simplicity, assume that the car has to travel from west to east in a straight line. There are various fuel stations on the way that are represented as a 2-D array of stations, i.e., stations[i] $= [d_i, f_i]$, where $d_i$ is the distance (in miles) of the $i^{th}$ gas station from the starting position, and $f_i$ is the amount of fuel (in liters) that it stores. Initially, the car starts with k liters of fuel. The car consumes one liter of fuel for every mile traveled. Upon reaching a gas station, the car can stop and refuel using all the petrol stored at the station. If it cannot reach the target, the program returns $−1$. ...