This is the CS50 lecture 4. Harvard All Rights Reserved.

1. This is CS50

2. CS50 IDE

3. check50
debug50
help50
printf
style50

4. valgrind

5. ddb50

7. string

8. char *

13. void swap(int a, int b)
{
int tmp = a;
a = b;
b = tmp;
}

14. void swap(int *a, int *b)
{
int tmp = *a;
*a = *b;
*b = tmp;
}

17. int main(void)
{
int *x;
int *y;
x = malloc(sizeof(int));
*x = 42;
*y = 13;
y = x;
*y = 13;
}

18. struct

22. array

23. linked list
tree
hash table
trie

24. https://cs.calvin.edu/activities/books/c++/ds/1e/

25. https://cs.calvin.edu/activities/books/c++/ds/1e/

26. string name;
string dorm;

27. typedef struct
{
string name;
string dorm;
}
student;

28. int n;

29. typedef struct node
{
int n;
}
node;

30. typedef struct node
{
int n;
node *next;
}
node;

31. typedef struct node
{
int n;
struct node *next;
}
node;

33. https://cs.calvin.edu/activities/books/c++/ds/1e/

34. int n;

35. typedef struct node
{
int n;
}
node;

36. typedef struct node
{
int n;
struct node *left;
struct node *right;
}
node;

37. bool search(int n, node *tree)
{
if (tree == NULL)
{
return false;
}
else if (n < tree->n)
{
return search(n, tree->left);
}
else if (n > tree->n)
{
return search(n, tree->right);
}
else
{
return true;
}
}

38. Figure from Lewis and Denenberg’s Data Structures & Their Algorithms.

39. This is CS50