栈和队列

迈不过友情╰ 2022-06-18 07:54 143阅读 0赞

栈：

package Suan;
    
    public class Stack {
         private int size;
         private int[] array;
         private int top;
         
         Stack(int size){
        	 this.size=size;
        	 array=new int[size];
        	 top=-1;
         }
         public  void push(int i){
        	 array[++top]=i;
         }
         
         public int pop(){//虽然数据还在，但是新加进来的数据会覆盖掉原数据
        	 return array[top--];
         }
         
         public boolean isEmpty(){
        	 return top==-1;
         }
         public boolean isFull(){
        	 return top==size-1;
         }
         
         public static void main(String[] args) {
    		Stack a = new Stack(5);
    		a.push(34);
    		a.push(23);
    		a.push(12);
    		a.push(67);
    		a.push(2);
    		System.out.println(a.isFull());
    		System.out.println(a.pop());
    	}
    }

可以用于单词逆序，和分隔符匹配如()\{\}\[\]。

队列：

package Suan;
    
    public class Queue {
                private int items;
    	    private int[] array;
    	    private int first;
    	    private int last;
    	     
    	    Queue(int size){
    	    	 this.items=0;
    	    	 array=new int[size];
    	    	 first=0;
    	    	 last=-1;
    	     }
    	    
    	   public void insert(int i){
    		   if(last==array.length-1){
    			   last=-1;
    		   }
    		   array[++last]=i;
    		   items++;
    	   }
    	   public int remove(){
    		   int a = array[first++];
    		   if(first==array.length){
    			   first=0;
    		   }
    		   items--;
    		   return a;
    	   }
    	   
    	   public boolean isEmpty(){
    		   return items==0;
    	   }
    	   public boolean isFull(){
    		   return items==array.length;
    	   }
    	   
    	   
    }

优先级队列：

package Suan;
    
    public class PriorityQueue {
    	private int items;
        private int[] array;
        
        public PriorityQueue(int size) {
        	array=new int[size];
        	items=0;
    	}
        
        public void insert(int i){
        	int j=0;
        	if(items==0){
        		array[items++]=i;
        	}else{
        		for(j=items-1;j>=0;j--){
        			if(i>array[j]){
        				array[j+1]=array[j];
        			}else{
        				break;
        			}
        		}
        		array[j+1]=i;
        		items++;
        	}
        }
        public int remove(){
        	return array[--items];
        }
        public boolean isEmpty(){
        	return items==0;
        }
        public boolean isFull(){
        	return items==array.length;
        }
        public static void main(String[] args) {
    		PriorityQueue a = new PriorityQueue(5);
    		a.insert(34);
    		a.insert(23);
    		a.insert(45);
    		a.insert(12);
    		System.out.println(a.remove());
    		System.out.println(a.remove());
    		System.out.println(a.remove());
    	}
    }