Reflective Questions (30 points)

Limit your answers to one paragraph or less.  You may do research but your writing must be your own; your answers may be checked for plagiarism.

1. Explain the difference between a statically allocated array, a dynamically allocated array, and a linked list.

2. Linked lists have terrible performance for random access or searching of internal entries. Why?

3. Explain the advantages of adding a tail pointer to a linked list, and of doubly-linked over singly-linked lists.

Introductory Performance Analysis (20 points)

4. A simple sorting algorithm has quadratic   It takes three minutes to sort a list of 10,000 entries.  How long do you expect it to take to sort a list of 100 entries?  How did you arrive at your answer?

5. A binary searching algorithm has logarithmic   It takes a second to find an item in a list of 10,000 entries.  How long do you expect it to take to find an item in a list of 10,000,000 entries?  How did you arrive at your answer?

6. A naïve searching algorithm took a second to find an item in a list of 500 entries and two seconds to find an item in a list of 1,000 entries. Estimate its runtime in terms of entries, in milliseconds. How did you arrive at your answer?

7. An unknown searching algorithm took a second to find an item in a list of 500 entries, two seconds to find an item in a list of 5,000 entries, and three seconds to find an item in a list of 50,000 entries. Estimate its runtime in big-   How did you arrive at your answer?

Dynamic Memory Management (25 points)

With the following structures allocated:

typedef struct {

char *name;

int commonality;

int weight;

} monster;

typedef struct {

char *name;

char *description;

double area;

int nmonsters;

monster *monsters;

} region;

typedef struct {

char *name;

double diameter;

int nregions;

region *regions;

} planet;

• Write functions to free all memory allocated for a planet, its child regions, and their child monsters.
• The functions should call each other as appropriate – use functions to free enclosed structures.
• Don’t free any memory that wouldn’t have been allocated.
• Don’t free anything more than once.
• Don’t worry about headers.
• Your function prototypes should be:

void dispose_monster(monster *monster);

void dispose_region(region *region);

void dispose_planet(planet *planet);

Linked Lists (25 points)

Coding: 15 points

With the following structures defined:

struct monster_struct {

char *name;

int commonality;

int weight;

struct monster_struct *next;

};

typedef struct monster_struct monster;

typedef struct monster_list {

monster *head;

}

• Write functions to return the second-most-common monster and the third-lightest monster in the list.
• Don’t worry about headers.
• Don’t worry about which way to resolve ties.
• The list will always have three monsters in it.
• Your function prototypes should be:

monster *second_most_common(monster_list *ml);

monster *third_lightest(monster_list *ml);

Analysis: 10 points

1. In big-terms what is the performance of each function?  Why?
2. Would either adding a tail pointer to the list, or making it a doubly-linked list, increase performance? Why or why not?