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Last active July 8, 2024 06:46
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This is a basic array based implementation of stack data structure in C.
// Stack - Array based implementation.
// Creating a stack of integers.
#include<stdio.h>
#define MAX_SIZE 101
int A[MAX_SIZE]; // integer array to store the stack
int top = -1; // variable to mark top of stack in array
// Push operation to insert an element on top of stack.
void Push(int x)
{
if(top == MAX_SIZE -1) { // overflow case.
printf("Error: stack overflow\n");
return;
}
A[++top] = x;
}
// Pop operation to remove an element from top of stack.
void Pop()
{
if(top == -1) { // If stack is empty, pop should throw error.
printf("Error: No element to pop\n");
return;
}
top--;
}
// Top operation to return element at top of stack.
int Top()
{
return A[top];
}
// This function will return 1 (true) if stack is empty, 0 (false) otherwise
int IsEmpty()
{
if(top == -1) return 1;
return 0;
}
// This function is just to test the implementation of stack.
// This will print all the elements in the stack at any stage.
void Print() {
int i;
printf("Stack: ");
for(i = 0;i<=top;i++)
printf("%d ",A[i]);
printf("\n");
}
int main() {
// Code to test the implementation.
// calling Print() after each push or pop to see the state of stack.
Push(2);Print();
Push(5);Print();
Push(10);Print();
Pop();Print();
Push(12);Print();
}
@Dipk05
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Dipk05 commented Sep 17, 2017

Helpful

@sgrpwr
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sgrpwr commented Oct 6, 2017

This is the best implementation of stack I've every seen. Thank you :)

@patrickpatso
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thanks a lot sir

@rohitrohan2009
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Thanks a lot, sir. I have used this code in my assignment of Stack implementation.

@Inquizarus
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I just found this through youtube today, thanks for the clear explanations .

One question though!

Isn't this Pop implementation wrong? This implementation only decreases the top index value but
nothing is removed/cleared from the array, so in reality the 10 is still there when printing after the pop and is
then overwritten by the value 12 before next print.

I'm not very familiar with C code at all so perhaps this is something that is taken care of for you?

@aman-roy
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aman-roy commented Jun 7, 2018

@Inquizarus If you see the implementation of Print() function then your doubt will be cleared. When we are doing the print, We are only concerned about the values till the top. What is after that is just garbage value for us. Whenever we want to push a new element, Only then we increase the top value by 1 and put our value there. Now the print function will look only till our new top, not after that.

@arjun0699
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thanks for the whole series on data structures.

@atharva-mishra
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nice explanation

@uday966666
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how can you implement this using struct in c
not using arrays data structure

@javeedsanganakal
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javeedsanganakal commented Mar 27, 2019

Find this Guy, Where he is.....We want all Subjects of CS

@hmsathyajith
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what is that time-consuming concept? I couldn't get it.

@kazinoman
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if(We learn) {
printf("That's awesome Sir.");
}
printf("Try again to learn.");

@abhishek-dash
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very efficient!!!

@SanjeevAshoka
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Sir, while printing elements of the stack -you are not accessing it from the top(as stack follow the rule of LIFO).
How is this code is working?.......

@adityakishan2018
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@SanjeevAshoka He implemented print function just to verify the present state of stack after each pop/push operation. He need not follow LIFO order for that.

@asadasivam
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Is there a source code for stack using struct/ object implementation?

@konpozzhr
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Thank a lot sir

@shania-balkhi
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Thank you!

@gethubusercp
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I just found this through youtube today, thanks for the clear explanations .

One question though!

Isn't this Pop implementation wrong? This implementation only decreases the top index value but nothing is removed/cleared from the array, so in reality the 10 is still there when printing after the pop and is then overwritten by the value 12 before next print.

I'm not very familiar with C code at all so perhaps this is something that is taken care of for you?
When you change top, you will not print the extra number, for you just print elements from 0 to top, the element is still there, but it doesn't matter, for you can overwritten it with push operation.

@SanjeevAshoka
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SanjeevAshoka commented Oct 18, 2021 via email

@piyushpp07
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Find this Guy, Where he is.....We want all Subjects of CS

his friend is no longer so the stopped uploading videos

@ShubhamJagtap2000
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There are 6 error showing while compiling the programme

They have provided raw code, you can have your own one

@ShubhamJagtap2000
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Find this Guy, Where he is.....We want all Subjects of CS

his friend is no longer so the stopped uploading videos

So sad, how did you know?

@gethubusercp
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Find this Guy, Where he is.....We want all Subjects of CS

his friend is no longer so the stopped uploading videos

So sad, how did you know?

You can know more about the author through this article-->https://www.freecodecamp.org/news/mycodeschool-youtube-channel-history/

@HaozeLiu
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Your video is very helpful for me,it really got me started with data structures.

@ericBlack1
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Thanks alot

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