28 lines
595 B
Java
28 lines
595 B
Java
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public class Stack<T>
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{
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private Node<T> first;
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public Stack(){
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this.first = null;
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}
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public boolean isEmpty(){
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return this.first == null;
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}
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public void push(T val){
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Node<T> added = new Node<T>(val);
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added.next = this.first;
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this.first = added;
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}
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public T pop (){
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if (this.first == null) return null;
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T ret = this.first.wert;
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this.first = this.first.next;
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return ret;
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}
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public T top (){
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if (this.first == null) return null;
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return this.first.wert;
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}
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}
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