Please explain each step

Problem 1 Starting with a map represented by a rectangular grid with height h and width w. Cells are numbered (0,0) in the top left to (h-1, -1) in the bottom right. Each cel in the grid is either empty or contains an impassable object. All movements on the map are done as a single step to a cell that is adjacent horizontally or vertically. No diagonal movement is permitted. (a) 0 Write an algorithm that uses a breadth first search to find the length of the shortest path from (0,0) to (w 1, h . Return -1 if no such path exists. (b) [5 What is the worst case complexity for your algorithm? Be sure to specify how the input size is measured and show your work. (c) [10] Modify your algorithm from part (a) to return the shortest path from (0,0) to (w - 1,h 1) in addition to its length. How does your change affect the time complexity? How does your change affect the amount of memory required