Project of data structure
Download as PPTX, PDF4 likes4,961 views
The document discusses various applications of stacks including: 1) Reversing strings by pushing characters onto a stack and popping them off in reverse order. 2) Calculator operations using postfix notation and a stack. 3) Recursive functions using a stack to store previous function calls and variables. 4) Determining if a word is a palindrome by pushing characters onto a stack and comparing to the popped off characters. Code examples are provided for reversing strings, recursive summation, and determining palindromes using stacks.
![#SOURCE CODE:
void push(int *top, element
item)
{
/* add an item to the global
stack */
if (*top >=
MAX_STACK_SIZE-1) {
stack_full( );
return;
}
stack[++*top] = item;
}
Push
element pop(int *top)
{
/* return the top element
from the stack */
if (*top == -1)
return
stack_empty( );
/* returns and error key */
return stack[(*top)--];
}
Pop](https://image.slidesharecdn.com/project-copy-160404081828/85/Project-of-data-structure-8-320.jpg)
![#define MAX 20
int top = -1;
char stack[MAX];
char pop();
void push(char);
main()
{
char str[20];
int i;
printf(“Enter the string : ” );
gets(str);
for(i=0;i<strlen(str);i++)
push(str[i]);
for(i=0;i<strlen(str);i++)
str[i]=pop();
printf(“Reversed string is : “);
puts(str);
void push(char item){
if(top == (MAX-1))
{
printf(“Stack Overflown”);
return;
}
stack[++top] =item;
}/*End of push()*/
char pop(){
if(top == -1)
{
printf(“Stack Underflown”);
exit(1);
}
return stack[top–];
}](https://image.slidesharecdn.com/project-copy-160404081828/85/Project-of-data-structure-12-320.jpg)
![Source code:
char stk[50];
int top=-1;
void push(char c){
top++;
stk[top]=c;
}
char pop(){
char c;
c=stk[top];
top–;
return c;
}
void main(){
char in[30],b[30];
int i;
printf(“nn ENTER UR STRINGt”);
gets(in);
for(i=0;in[i]!=‘’;i++){
push(in[i]);
}
i=0;
while(top!=-1){
b[i]=pop();
i++;
}
b[i]=‘’;
if(strcmp(in,b)==0){
printf (“n STRING is
PALLINDROME”);
}
else{
printf (“n STRING IS NOT
PALLNDROME”);
}
}](https://image.slidesharecdn.com/project-copy-160404081828/85/Project-of-data-structure-23-320.jpg)
Project of data structure
- 2. STACK
- 5. A stack is a data structure that stores data in such a way that the last piece of data stored, is the first one retrieved. LAST IN FIRST OUT =LIFO To get the bottom plate out, you must first remove all the plates above. Example of stack
- 6. All these applications follow the LIFO logic. REAL LIFE: Stacks are present everyday life.From the books in a library, to the blank sheets of paper in a printer tray systems are used STACK to complete their acts. #PILES OF BOOKS: A book is added on top of a pile of books, while removing a book from a pile also takes the book on top of a pile in everywhere.
- 8. #SOURCE CODE: void push(int *top, element item) { /* add an item to the global stack */ if (*top >= MAX_STACK_SIZE-1) { stack_full( ); return; } stack[++*top] = item; } Push element pop(int *top) { /* return the top element from the stack */ if (*top == -1) return stack_empty( ); /* returns and error key */ return stack[(*top)--]; } Pop
- 10. RLATEDTO COMPUTER SCIENCE: Below are a few applications of stacks in computing. #REVERSING STRING: A simple application of stack is reversing strings. To reverse a string , the characters of string are pushed onto the stack one by one as the string is read from left to right. To reverse the string ‘REVERSE’ the string is read from left to right and its characters are pushed.LIKE:
- 11. E S R E V E R REVERSE ESREVER String is Reverse String Stack #VISULAZE STAGE:
- 12. #define MAX 20 int top = -1; char stack[MAX]; char pop(); void push(char); main() { char str[20]; int i; printf(“Enter the string : ” ); gets(str); for(i=0;i<strlen(str);i++) push(str[i]); for(i=0;i<strlen(str);i++) str[i]=pop(); printf(“Reversed string is : “); puts(str); void push(char item){ if(top == (MAX-1)) { printf(“Stack Overflown”); return; } stack[++top] =item; }/*End of push()*/ char pop(){ if(top == -1) { printf(“Stack Underflown”); exit(1); } return stack[top–]; }
- 14. #Calculator Methodology: Every arithmetic operation in calculator follow the stack postfix notation. * + 9 6 39+6*3 Equation Postfix string Stack
- 15. Create Stack While(not end of postfix notation){ ch = getch() if(ch is operand) push(ch) else{ operand1 = pop() operand2 = pop() result = operand2 ch operand1 push(result) } } Result = pop()
- 17. #Function ( recursive ): A very good example of stack is Function. Summation of positive integer can be implemented by recursive function and the functions are stored in a stack to maintain the sequence of summation. When a function is called within a function then the previous function is stored in a stack with it’s local variables. Summation of positive numbers with code example:
- 18. #include <stdio.h> int sum(int n); int main(){ int num,add; printf("Enter a positive integer:n"); scanf("%d",&num); add=sum(num); printf("sum=%d",add); } int sum(int n){ if(n==0) return n; else return n+sum(n-1); /*self call to function sum() */ } Enter a positive integer: 5 15 Output
- 19. For better visualization of recursion in this example: sum(5) =5+sum(4) =5+4+sum(3) =5+4+3+sum(2) =5+4+3+2+sum(1) =5+4+3+2+1+sum(0) =5+4+3+2+1+0 =5+4+3+2+1 =5+4+3+3 =5+4+6 =5+10 =15 Sum(1) Sum(2) Sum(3) Sum(4) Sum(5) All functions are pushed in stack
- 21. Implementation : Palindrome A palindrome is a word, phrase, number, or other sequence of Characters which reads the same backward or forward. Allowances may be made for adjustments to capital letters, punctuation, and word dividers. Suppose : ABCDCBA is a palindrome FGHHGF is a palindrome ASDFASDF is not a palindrome
- 22. C I V I C C I V I C PUSH POP Stack Stack Palindrome Word After pushing and popping, CIVIC word remain unchanged #VISULAZE STAGE:
- 23. Source code: char stk[50]; int top=-1; void push(char c){ top++; stk[top]=c; } char pop(){ char c; c=stk[top]; top–; return c; } void main(){ char in[30],b[30]; int i; printf(“nn ENTER UR STRINGt”); gets(in); for(i=0;in[i]!=‘’;i++){ push(in[i]); } i=0; while(top!=-1){ b[i]=pop(); i++; } b[i]=‘’; if(strcmp(in,b)==0){ printf (“n STRING is PALLINDROME”); } else{ printf (“n STRING IS NOT PALLNDROME”); } }
- 24. ThankYou