Solving 8-Puzzle manually varies from person to person. To solve it by computer or AI, we need a bit of a basic understanding of how it works to get the Goal node.
Following are the steps:
Get the current state of the scenario (refers to the board or game in real world).
Find the available moves and their cost.
Choose the move with the least cost and set it as the current state.
Check if it matches the goal state, if yes terminate, if no move to step 1.
In the code, our agent (program) will look for an empty space ('0') in a state and then which moves are allowed and have the least cost. As a result it will move towards the goal which is our final state