[DataStructures] 스택(Stack) - 제네릭스택(Stack Using Generic)

스택(Stack) - 제네릭스택(Stack Using Generic)

- 제네릭을 이용하여 String, int 등 다양하게 받을 수 있다

1. 구현

1) 초기화

public class StackUsingGeneric <T extends Object>{ private int stackSize; private int top; private T[] stackArr; public StackUsingGeneric(int size){ this.stackSize = size; this.top = -1; this.stackArr = (T[]) new Object[stackSize]; }

- T 로 선언하여 객체 형태의 따라 받을 수 있게 한다

2) push(), isStackFull(), increaseCapacity()

public void push(T element){ if(this.isStackFull()){ System.out.println("Stack is full"); this.increaseCapacity(); } System.out.println("adding:"+element); this.stackArr[++top] = element; } public boolean isStackFull(){ return (this.stackSize -1 == top); } public void increaseCapacity(){ T[] newArr = (T[]) new Object[stackSize * 2]; for(int i = 0; i<stackSize; i++){ newArr[i] = stackArr[i]; } this.stackArr = newArr; this.stackSize = this.stackSize *2; }  

3) pop(), isStackEmpty(), peek()

public T pop()throws Exception{ if(this.isStackEmpty()){ throw new Exception("Stack is empty"); } System.out.println("removing:"+stackArr[top]); return stackArr[top--]; } public T peek(){ System.out.println("peeking:"+this.stackArr[top]); return this.stackArr[top]; }  

4) main()

public static void main(String[]args){ StackUsingGeneric<Integer> a1 = new StackUsingGeneric(2); try{ a1.push(1); a1.push(2); a1.peek(); a1.push(3); a1.pop(); }catch(Exception e){ System.out.print(e.getMessage()); } StackUsingGeneric<String> a2 = new StackUsingGeneric(2); try{ a2.push("a"); a2.push("b"); a2.peek(); a2.push("c"); a2.pop(); }catch(Exception e){ System.out.print(e.getMessage()); } }  

- 객체를 String, Integer 두개로 생성