面试题09. 用两个栈实现队列

绝地灬酷狼 2023-05-28 11:17 13阅读 0赞

# 题目： #

[面试题09. 用两个栈实现队列][09.]  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3p5eF9seQ_size_16_color_FFFFFF_t_70]

# 题解： #

[232. 用栈实现队列][232.]

# 代码： #

/** * 面试题09 */
    import java.util.*;
    
    public class 面试题09 { 
    
        public static class CQueue { 
    
            Stack<Integer> s1; // 输入栈
            Stack<Integer> s2; // 输出栈
    
            public CQueue() { 
                s1 = new Stack<>();
                s2 = new Stack<>();
            }
    
            public void appendTail(int value) { 
                s1.push(value);
            }
    
            public int deleteHead() { 
                if (s1.empty() && s2.empty()) { 
                    return -1;
                }
                if (s2.isEmpty()) { 
                    while (!s1.isEmpty()) { 
                        s2.push(s1.pop());
                    }
                }
                return s2.pop();
            }
        }
    
        public static void main(String[] args) { 
            CQueue obj = new CQueue();
            int value = 5;
            obj.appendTail(value);
            int param_2 = obj.deleteHead();
            System.out.println(param_2);
        }
    }

# 参考： #

![无。][20200325233219667.png]

class CQueue { 
        LinkedList<Integer> stack1;
    	LinkedList<Integer> stack2;
    
    	public CQueue() { 
    		stack1 = new LinkedList<>();
    		stack2 = new LinkedList<>();
    	}
    
    	public void appendTail(int value) { 
    		stack1.add(value);
    	}
    
    	public int deleteHead() { 
    		if (stack2.isEmpty()) { 
    			if (stack1.isEmpty()) return -1;
    			while (!stack1.isEmpty()) { 
    				stack2.add(stack1.pop());
    			}
    			return stack2.pop();
    		} else return stack2.pop();
    	}
    }

[09.]: https://leetcode-cn.com/problems/yong-liang-ge-zhan-shi-xian-dui-lie-lcof/
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3p5eF9seQ_size_16_color_FFFFFF_t_70]: /images/20230528/2b606690cd1247718c4ea1c914e3c5f0.png
[232.]: https://blog.csdn.net/zyx_ly/article/details/104527670
[20200325233219667.png]: /images/20230528/3e8b49c2ba1944058bfc088db636f9b6.png