CS 223 - Spring 2017. 3/27

Welcome to CS 223!

Larry Wall Quote of the day

The road to heaven is paved with good extensions.

Logical problem of the day

char *f(){ 
  char result[80]; 
  sprintf(result,"anything will do"); 
  return(result);   
}

int main(int argc, char **argv){ 
  char *p; 
  p = f(); 
  printf("f() returns: %s\n",p);
}

What's up up there?

Lecture 16: HW5 + Data Structures: btrees, AVL trees, heaps

Administrivia

Office hours:

The office hours are Sun/Tue/Thu 8-11 PM at Hillhouse 17 Rm 111.

My office hours this week are Wednesday 3-5pm.

https://www.startupyale.com/prizes/ Yale Prizes $25,000: deadline 3/30/17.

http://yalecompsociety.org/prize

Assignment 5 - Revision

Problem set 5 revision

Add balanced tree option to hw5, using -avl flag.

See /c/cs223/hw5/Cloudavlx

See AVL Trees AVLtree.h AVLtree.c AVLtree.output

Here is one way to do it: (how I did it)

Rewrite AVLtree.h and AVLtree.c to use string keys instead of integer keys. You should test to make sure that this works before going further. (Does not use **root**.)

In AVLtree.c, undefine:

#define TEST_MAIN
#define PRINT_AFTER_OPERATIONS

Modify Makefile to create .o file and link in with Cloud:

Cloud:  Cloud.o btree.o AVLtree.o
	${CC} ${CFLAGS} -o Cloud Cloud.o btree.o AVLtree.o

AVLtree.o: AVLtree.c
	${CC} ${CFLAGS} -c AVLtree.c

In AVLtree.h and AVLtree.c, rename functions that conflict with function names in btree.h, e.g., treeHeight() could be avlHeight()
In Cloud.c, check for the -avl command line argument. If present, create an AVL tree. Otherwise, use your btree. Modify your code accordingly, calling the AVL functions or btree functions as appropriate. Also, the avl debug option prints out the tree, unlike the btree option.

Lecture Starts Here

Binary Trees

A btree for integers btreeint.c (from Aspnes) [malloc issue: sizeof(struct node) == sizeof(*newNode) != sizeof(newNode)] -- added treePrint()
A btree for integers btreeintargs.c with command line arguments. -- added treePrint()
The header file btree.h Note: there is no treeDelete function. (sigh of relief)
The test file btreetest.c (continue here) -- added treePrint()
The arg test file btreetestargs.c -- added treePrint()
Data Structure Visualizations
Binary search tree animation
Balanced trees
AVL Trees AVLtree.h AVLtree.c AVLtree.output AVL animation
Next: graphs and heaps!

[Home]