1 Stack-oop

The stack implements the last-in-first-out (advanced-out) strategy, and the queue implements the FIFO strategy.

1 Stacks the operations on the stack mainly include

1. The insert operation is called Press-in (push). Note the overflow problem, which is to add elements to the full stack.
2. A delete operation with no parameter version is called eject (pop). Note the underflow problem, which is to take the element from the empty stack.
3. Stack-empty to determine if the stack is empty

the idea of the stack implementation

Use an array of S[1..N] to implement a stack that accommodates up to n elements. The array has a parameter s.top to indicate where to insert the element, S[0] is the bottom of the stack, and S[s.top-1] is the top of the stack.

Pseudo code

1. Determine if the stack is empty:

empty()if0    returntrueelse     returnfalse

2. Insert Push

if top > size    error"upflow"else    stack[top] =x;    top=top+1

3. Delete Pop

if empty()    "underflow"else    poppop-1    return stack[pop]   

Template implementation of the stack

#include <iostream>Template<classTConst intSize = ->classstack{T S[size];intTop Public: Stack (): Top (0){}BOOLEmpty () {returntop = =0;} T Pop () {if(Top <=0){STD::Cerr<<"Underflow";Exit(0); }returnS[--top]; }voidPush (T t) {if(Top >= size) {STD::Cerr<<"Overflow";Exit(0);    } s[top++] = t; }};//test codeintMain () {Const intSize =Ten; stack<int, size> si; for(inti =0; i < size; i++) {STD::cout<< i;    Si.push (i); }STD::cout<<STD:: Endl; while(!si.empty ())STD::cout<< Si.pop ();}

Implement two stacks in an array so that when the sum of the two stack elements is not n, it will not overflow. Push and pop operations run at O (1)

To have 2 stacks common one storage space, the stack top pointer starts from both ends, and overflows when the two pointers point to the same memory.

#include <iostream>Template<classTConst intSize = ->classstack{T S[size];intTOP1;intTOP2; Public: Stack (): Top1 (0), TOP2 (size-1){}BOOLEmptyintIndex) {if(Index = =1)returnTOP1 = =0;Else            returnTOP2 = = size-1; } T POPs (intIndex) {if(Index = =1&& TOP1 = =0){STD::Cerr<<"Underflow";Exit(0); }if(Index = =2&& TOP2 = = size-1){STD::Cerr<<"Underflow";Exit(0); }if(Index = =1)returnS[--TOP1];Else            returnS[++TOP2]; }voidPush (T T,intIndex) {if(Top1 = = TOP2) {STD::Cerr<<"Overflow";Exit(0); }if(Index = =1) s[top1++] = t;Elses[top2--] = t; }};intMain () {Const intSize =Ten; stack<int, size> si; for(inti =0; I <4; i++) {STD::cout<< i; Si.push (I,1); }STD::cout<<STD:: Endl; for(inti =0; I <5; i++) {STD::cout<< i; Si.push (I,2); }STD::cout<<STD:: Endl; while(!si.empty (1))STD::cout<< Si.pop (1);STD::cout<<STD:: Endl; while(!si.empty (2))STD::cout<< Si.pop (2);}

1 Stack-oop