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最新推荐文章于 2024-12-10 18:20:29 发布

最新推荐文章于 2024-12-10 18:20:29 发布 · 185 阅读

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本文介绍了一个自定义的数据结构 MinMaxStack，该结构继承自泛型接口 IMinMaxStack，能够实现在栈中快速获取最大值和最小值的功能。通过对栈的内部实现进行特殊设计，确保了这些操作的时间效率。

public interface IMinMaxStack<T> {

	public T pop();
	public void push(T t);
	public T getMin();
	public T getMax();
	public int getLength();
}

public class MinMaxStack implements IMinMaxStack<Integer> {

	private static int maxLength = 5;
	private static int [] data= new int[maxLength];
	private static int [] mins= new int[maxLength];
	private static int [] maxs= new int[maxLength];
	private static int size = 0;
	private static int current = 0;
	private static int total = 0;

	private void growing(){
		if (current >= maxLength / 4  * 3 ) {
			maxLength = (maxLength *3)/2 + 1;
			data = Arrays.copyOf(data, maxLength);
			mins = Arrays.copyOf(mins, maxLength);
			maxs = Arrays.copyOf(maxs, maxLength);
		 }
	}
	
	@Override
	public Integer pop() {
		total --;
		if (current >= 0) {
			 int temp =	data[current-1] ;
			   current --;
			   return temp;
		}
		return null;
	}

	@Override
	public void push(Integer t) {
		total ++;
		growing();
		data[current] = t;  
		if(current == 0){
			mins[current] = t;
			maxs[current] = t;
		}else{
			if (mins[current-1] >= t) {
				mins[current] = t; 
			}else{
				mins[current] = mins[current-1]; 
			}
			if (maxs[current-1] <= t) {
				maxs[current] = t;
			}else{ 
				maxs[current] = maxs[current-1];
			}
			
		}
		current ++;
	}
 
	@Override
	public Integer getMin() {
		int temp = mins[current];
		return temp;
	}
 
	@Override
	public Integer getMax() { 
		int temp = maxs[current];
		return temp;
	}
	
	@Override
	public int getLength() { 
		return total;
	}
 

	 
	 public static void main(String[] args) {
		 MinMaxStack  ms = new MinMaxStack();
		 ms.push(6);
		 ms.push(2);
		 ms.push(7);
		 ms.push(1);
		 ms.push(5);
		 ms.push(3);
		 System.out.println("current\tlength\tpop\tmin\tmax");       
		 System.out.println(ms.current+"\t"+ms.getLength()+"\t"+ms.pop()+"\t"+ ms.getMin()+"\t"+ ms.getMax());       
		 System.out.println(ms.current+"\t"+ms.getLength()+"\t"+ms.pop()+"\t"+ ms.getMin()+"\t"+ ms.getMax());       
		 System.out.println(ms.current+"\t"+ms.getLength()+"\t"+ms.pop()+"\t"+ ms.getMin()+"\t"+ ms.getMax());       
		 System.out.println(ms.current+"\t"+ms.getLength()+"\t"+ms.pop()+"\t"+ ms.getMin()+"\t"+ ms.getMax());       
		 System.out.println(ms.current+"\t"+ms.getLength()+"\t"+ms.pop()+"\t"+ ms.getMin()+"\t"+ ms.getMax());       
		 System.out.println(ms.current+"\t"+ms.getLength()+"\t"+ms.pop()+"\t"+ ms.getMin()+"\t"+ ms.getMax());       
	 }
}