Consider a search problem to sort a horizontal row of tiles, where each move in the search swaps a pair of adjacent tiles. The following shows the start and end states: 3 4 1 2 1 2 3 4 A move consists of swapping the position of two adjacent numbers, as shown below: 3412 3421 The distance d; for digit i is the number of positions it is from its goal position. On paper generate the A* search tree, when the heuristic used is h(x)= d; and hence fill in the missing values in the table shown expanding this as necessary. Some of this is completed for you already. For each child node added to the tree, you need to fill in 4 values. The first is the value of the state. This is a 4-digit number corresponding to the 4 ordered tiles. The initial state is the number 3412 and the goal state is 1234 and every