1. 实现一个栈，可以在最小时间复杂度内计算出栈中的最小值。空间复杂度无视。

package lime.xiaoniu;import java.util.Iterator;import java.util.Stack;/** * 实现一个栈，可以在最小时间复杂度内计算出栈中的最小值。空间复杂度无视。 */public class DevilStack {    public static void main(String[] args){        DevilStack stack = new DevilStack();        for(int i = 10;i > 0;i--){            stack.push((int)(Math.random() * 100));        }        stack.inOrder();        while (!stack.isEmpty()){            System.out.println("mixStackPop : " + stack.peekMixData() + " dataStackPop : " + stack.pop());        }    }    private Stack
     
       dataStack = new Stack
      
       ();    private Stack
       
         mixStack = new Stack
        
         ();    private Integer mixData = Integer.MAX_VALUE;    public boolean push(Integer data){        if(null == data){            return false;        }        dataStack.push(data);        mixStack.push(mixData = Math.min(mixData,data));        return true;    }    public Integer pop(){        if(dataStack.isEmpty()){            return null;        }        mixStack.pop();        return dataStack.pop();    }    public Integer peekMixData(){        if(dataStack.isEmpty()){            return null;        }        return mixStack.peek();    }    public void inOrder(){        if(dataStack.isEmpty()){            return;        }        Iterator
         
           iterator = dataStack.iterator();        System.out.print("dataStack : " );        for(;iterator.hasNext();){            System.out.print(iterator.next() + "  ");        }        System.out.print("\nmixStack : ");        for(iterator = mixStack.iterator();iterator.hasNext();){            System.out.print(iterator.next() + "  ");        }        System.out.println();    }    public boolean isEmpty(){        return dataStack.isEmpty();    }}
         
        
       
      
     

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