XIICSSTACK_INTRODUCTION cs

cs

1. TOPIC : INTRODUCTION OF STACK

2. Stack
•StackisalinearDataStructureimplementedinLIFO(LastInFirst
Out)mannerwhereinsertionanddeletionofelementare
performedonlyatoneendi.e.topofthestack.
•Itisacollectionofdataitemsinwhichdataitemsareinsertedand
deletedfromthetopofstack.
•TheremovalofelementfromstackiscalledPOPoperation.
•TheinsertionofnewelementatthetopofthestackiscalledPUSH
operation.
•StackisalsocalledDynamicDataStructurebecausethestack
implementedbylistcangrow(i.e.increasenumberofelements)
andshrink(i.e.decreasethenumberofelements)

3. Representation of Stack
with Push and Pop operations

4. Other Stack Terms
1-Overflow:-Itreferstothesituationwhenonetriesto
push(insert)aniteminstackthatisalreadyfull.This
situationoccurswhenthesizeofstackisfixedandcan
notgroworthereisnomemorylefttoaccommodate
newitem.
2-Underflow:-Itreferstothesituationwhenonetriesto
pop(delete)anitemfromtheemptystack.
3-Peek:-Itreferstoinspectingorgetthevaluefromthetop
ofthestacki.e.Peekmeanstoknowthetopmost
elementofstack

5. Illustrating Overflow and Underflow Condition

6. Illustrating Overflow and Underflow Condition