C programming

Q:2. A) Given the conversion program from infix to postfix, trace the program on the given infix string and fill the table. (10 pts)

(A+ (B*C-(D/E^F)*G)*H), where ^ is an exponential operator.

1. #include

2. #include

3. #include

4. #define SIZE 50

5. char s[SIZE];

6. int top=-1;

7. push(char elem)

8. {

9. s[++top]=elem;

10. }

11.

12. char pop()

13. {

14. return(s[top--]);

15. }

16.

17. int pr(char elem)

18. {

19. switch(elem)

20. {

21. case '#': return 0;

22. case '(': return 3;

23. case '+':

24. case '-': return 2;

25. case '*':

26. case '/': return 3;

27. Case ^: return 4;

28. }

29. }

30.

31. void main()

32. {

33. char infx[50],pofx[50],ch,elem;

34. int i=0,k=0;

35. clrscr();

36. printf(" Read the Infix Expression ? ");

37. scanf("%s",infx);

38. push('#');

39. while( (ch=infx[i++]) != '\0')

40. {

41. if( ch == '(') push(ch);

42. else

43. if(isalnum(ch)) pofx[k++]=ch;

44. else

45. if( ch == ')')

46. {

47. while( s[top] != '(')

48. pofx[k++]=pop();

49. elem=pop();

50. }

51. else

52. {

53. while( pr(s[top]) > pr(ch) )

54. pofx[k++]=pop();

55. push(ch);

56. }

57. }

58. while( s[top] != '#')

59. pofx[k++]=pop();

60. pofx[k]='\0';

61. printf(" Given Infix Expn: %s Postfix Expn: %s ",infx,pofx);

62. getch();

Symbol No

Scanned

Stack

Postfix expression

Description (what action was performed)

1.

(

2.

A

3.

+

4.

(

5.

B

6.

*

7.

C

8.

-

9.

(

10.

D

11.

/

12.

E

13.

^

14.

F

15.

)

16.

*

17.

G

18.

)

19.

*

20.

H

21.

)