CS 371
Introduction to Artificial Intelligence
Homework #2

Due:  Tuesday, 9/12
  1. Informed Search: Consider the following graph where nodes are states, arcs are operators labeled with costs, values to the right of nodes are their heuristic evaluations, A is the initial state, and G is the goal state:
  2. In (a)-(d), you will give the order in which nodes are goal-tested according to different informed or heuristic search strategies employing different ways of avoiding repeated states. List the order of node goal-testing until the search terminates or 18 nodes have been listed. Ties in node ordering are broken alphabetically by state label.

    1. Greedy, no repeats
    2. A/A*, generate all
    3. IDA/IDA*, no cycles
    4. Is our heuristic evaluation function h admissible? Why or why not?
    5. Show why f is not monotonic.
    6. Modify f according to the pathmax equation.
  3. Multiple choice:
    1. The drawback of A* is that
      1. it takes more time than depth-first search
      2. it takes exponential space (in the depth of the goal)
      3. it may be difficult to find a (useful) admissible heuristic function.
      4. both ii,iii
      5. all of i,ii,iii
    2. Select the most space conserving search of those mentioned below:
      1. A* search with h(n) = 0 for all n
      2. iterative-deepening search
      3. breadth-first search
      4. A* search with an admissible heuristic
    3. One of the problems hill-climbing does not have is:
      1. the local-minima problem
      2. the plateau problem
      3. the horizon problem
      4. the ridge problem
  4. TripleCross Challenge #2:

(c) 2000 Todd Neller