树中节点间最长距离

2019独角兽企业重金招聘Python工程师标准>>>

import java.util.Stack;


public class Node {
    Node left;
    Node right;
    int maxLeft;
    int maxRight;
    int value;
    
    
    public static void main(String args[]){
    	Node node1 = new Node(null, null, 1);
    	Node node7 = new Node(null, null, 7);
    	Node node12 = new Node(null, null, 12);
    	Node node8 = new Node(null, node1, 8);
    	Node node4 = new Node(null, node8, 4);
    	
    	Node node5 = new Node(node4, node7, 5);
    	Node node10 = new Node(node12, node5,10);
    	Stack stack = new Stack();
    	//findPath(node10, 22, stack);
    	System.out.println(findMaxLen(node10));
    }
    
    public Node(Node left, Node right, int value){
    	this.left = left;
    	this.right = right;
    	this.value = value;
    }
    public static void findPath(Node node, int sum, Stack stack){
    	stack.push(node.value);
    	sum -= node.value;
    	if(sum == 0){
    		printPath(stack);
    	} 
    	if (node.left != null){
    		findPath(node.left, sum, stack);
    	}
    	if(node.right != null){
    		findPath(node.right, sum, stack);
    	}
    	sum += node.value;
    	stack.pop();
    	return;
    }
    
    public static void printPath(Stack stack){
    	Object objs[] = stack.toArray();
    	System.out.println();
    	for(Object obj : objs){
    		System.out.print(obj+"->");
    	}
    }
    
    public static int findMaxLen(Node node){
    	int maxLength = 0;
    	int maxLeftLength = 0;
    	int maxLeftHeight = 0;
    	int maxRightHeight = 0;
    	
    	if(node.left != null){
    		maxLeftHeight = findMaxHeight(node.left);
    		maxLeftLength = findMaxLen(node.left);
    	} 
    	
    	int maxRightLength = 0;
    	if(node.right != null){
    		maxRightHeight = findMaxHeight(node.right);
    		maxRightLength = findMaxLen(node.right);
    	}
    	
    	if(maxLeftLength > maxRightLength){
    		maxLength = maxLeftLength;
    	} else {
    		maxLength = maxRightLength;
    	}
    		
    	if(maxLength < maxLeftHeight + maxRightHeight){
    		maxLength = maxLeftHeight + maxRightHeight;
    	}
    	
    	return maxLength;
    }
    
    public static int findMaxHeight(Node node){
    	int maxHeigth = 0;
    	int maxLeftHeight = 0;
    	if(node.left != null){
    		maxLeftHeight = findMaxHeight(node.left);
    	} 
    	
    	int maxRightHeight = 0;
    	if(node.right != null){
    		maxRightHeight = findMaxHeight(node.right);
    	}
    	
    	if(maxLeftHeight > maxRightHeight){
    		maxHeigth =  maxLeftHeight + 1;
    	} else {
    		maxHeigth = maxRightHeight + 1; 
    				
    	}
    		
    	return maxHeigth;
    }
}

转载于:https://my.oschina.net/u/138995/blog/307838