2.  Last Lecture Reminder  Array Sorts  Exam Questions Examples  Open Questions ◦ Search Engines ◦ Operating Systems ◦ Multiple Files in Projects  Additional Lesson – before MOED ALEF

3.  Linked Lists  Files

4. 2345 Head Next Next = NULL

5. typedef struct link{ int data; struct link *next; }link;

6. void main(){ link *head=NULL, *temp=NULL; int d; printf("Enter the list values:\n"); scanf ("%d",&d); while (d!=-1){ temp=(link *)malloc(sizeof(link)); if (!temp) break; temp->next=head; temp->data=d; head=temp; scanf ("%d",&d); }  A list is presented by its head

7. while(temp){ printf("%d ",temp->data); temp=temp->next; } while (head){ temp=head->next; free(head); head=temp; }

8. void free_list(link *head) { if (head== NULL) /* Finished freeing. Empty list */ return; free_list(head->next); /* Recursively free what’s ahead */ free(head); }

10. C Program STDIN STDOUT STDERR FILE1 FILE2

11.  stdin  stdout  stderr

12. #include void main(){ int n; printf("hello world"); fprintf(stdout,"hello world"); fprintf(stderr,"hello world"); fscanf(stdin,"%d", &n); scanf("%d", &n); }

13. #include void main(){ FILE *f1; f1 = fopen(“test1.txt","w"); if(!f1){ printf("Error opening file!\n"); return; } fprintf(f1,"hello world"); fclose(f1); }

14. #include void main(){ char ch; FILE *f1; f1 = fopen(“test2.txt","r"); if(!f1){ printf("Error opening file!\n"); return; } fscanf(f1,"%c",&ch); fclose(f1); }

15.  Bubble Sort  Selection Sort  Insertion Sort  Merge Sort  Quick Sort

16. #include void main() { int i, j, min, temp, nums[10]; for (i=0; i<SIZE; i++){ /*input*/ printf ("enter number\n"); scanf ("%d",&nums[i]); } for (i=0; i<SIZE; i++){ /*main loop*/ for (j=0; j<SIZE-i-1; j++) /*finding smaller*/ if (nums[j]>nums[j+1]) { temp = nums[j]; /*swapping*/ nums[j] = nums[j+1]; nums[j+1] = temp; } for (i=0; i<SIZE; i++) /*printing*/ printf ("%d\n",nums[i]); }

17.  Unsorted array:  Effective array of size 6:  Effective array of size 5:  Effective array of size 4:  Effective array of size 3:  Effective array of size 2:  Effective array of size 1:  Sorted array:  45 67 12 34 25 39  45 12 34 25 39 67  12 34 25 39 45  12 25 34 39  12 25 34  12 25  12  12 25 34 39 45 67

18. 37591211527235779

19. #include void main() { int i, j, min, temp, nums[10]; for (i=0; i<10; i++){ /*input*/ printf ("enter number\n"); scanf ("%d",&nums[i]); } for (i=0; i<9; i++){ /*main loop*/ min = i; for (j=i+1; j<10; j++) /*finding minimum index*/ if (nums[j]<nums[min]) min = j; temp = nums[i]; /*swaping*/ nums[i] = nums[min]; nums[min] = temp; } for (i=0; i<10; i++) /*printing*/ printf ("%d\n",nums[i]); }

20. 375912

21. #include void main() { int i, j, temp, nums[10]; for (i=0; i<10; i++){ /*input*/ printf ("enter number\n"); scanf ("%d",&nums[i]); } for (i=0; i<10; i++){ /*main loop*/ /*finding location of nums[j]*/ for (j=i; j>0 && nums[j]<nums[j-1]; j--){ temp = nums[j]; /*swaping*/ nums[j] = nums[j-1]; nums[j-1] = temp; } for (i=0; i<10; i++) /*printing*/ printf ("%d\n",nums[i]); }

22. void mergeSort(int ar[],int lo,int hi){ if (lo<hi) { int m=(lo+hi)/2; mergeSort(ar,lo, m); mergeSort(ar, m+1, hi); merge(ar, lo, m, hi); }

23. #define SIZE 100 void merge(int a[],int lo,int m, int hi){ int i, j, k, b[SIZE]; for (i=lo; i<=hi; i++) b[i]=a[i]; i=lo; j=m+1; k=lo; while (i<=m && j<=hi) if (b[i]<=b[j]) a[k++]=b[i++]; else a[k++]=b[j++]; while (i<=m) a[k++]=b[i++]; }

25.  What’s printed on the screen when the following programs are run? ◦ printing.c ◦ change_val.c  What does this function do? ◦ secret.c

26.  Implement a function such that – ◦ Input: string s that contains (among other things) parentheses ◦ Output: 1 if the parentheses’ nesting is legal, 0 otherwise ◦ For example – (()())() is legal, while ())() and (()(()) are not.  Write a program that accepts a string from the user and checks the parentheses.

27.  Write a structure of a point in 2D space and a distance function between two points  Write a program that gets an array of points from the user and calculates the largest distance between a pair of points in the array  The size of the array is given by the user before the points are read in  Solution – max_distance.c

28.  Implement a linked list where each item simply contains an integer  Input a number n from the user, and split the original list into two lists such that the first contains all the elements smaller than n, and the other contains all the others  Display both linked lists on the screen

29.  Define two structures – a point and a circle  Implement a function is_in_circle that accepts a point and a circle, and returns 1 if the point is in the circle, 0 otherwise  Write a program that accepts input from user in the following order: ◦ n = the number of circles ◦ A point  And outputs the number of circles containing that point  n is user input!`

30.  Search Engines  Operating Systems  Multiple Files in Projects