對於堆中每一個X節點，左兒子的零路徑長至少與右兒子的零路徑長相等。
零路徑長：從X到一個不具有兩個兒子的節點的最短路徑長。

函式複雜度比較 
1）獲取最小值：        O（1）    
2）刪除Min：     O（Log n）   
3）插入：         O（Log n）                                                             
4）合併：         O（Log n）  

節點：

class LeftHeapNode
{
    int element, sValue;     
    LeftHeapNode left, right;             
 
    public LeftHeapNode(int ele)
    {
        this(ele, null, null);
    }
    public LeftHeapNode(int ele, LeftHeapNode left, LeftHeapNode right)
    {
        this.element = ele;
        this.left = left;
        this.right = right;
        this.sValue = 0;
    }    
}
 

操作API：

/** Class LeftistHeap **/
class LeftistHeap
{
    private LeftHeapNode root; 
 
    /** Constructor **/
    public LeftistHeap() 
    {
        root = null;
    }
 
    /** Check if heap is empty **/
    public boolean isEmpty() 
    {
        return root == null;
    }
 
    /** Make heap empty **/ 
    public void clear( )
    {
        root = null;
    }
 
    /** Function to insert data **/
    public void insert(int x )
    {
        root = merge(new LeftHeapNode( x ), root);
    }
 
    /** Function merge **/
    public void merge(LeftistHeap rhs)
    {
        if (this == rhs)    
            return;
        root = merge(root, rhs.root);
        rhs.root = null;
    }
 
    /** Function merge **/
    private LeftHeapNode merge(LeftHeapNode x, LeftHeapNode y)
    {
        if (x == null)
            return y;
        if (y == null)
            return x;
        if (x.element > y.element)
        {
            LeftHeapNode temp = x;
            x = y;
            y = temp;
        }
 
        x.right = merge(x.right, y);
 
          if(x.left == null) 
          {
            x.left = x.right;
            x.right = null;         
        } 
        else 
        {
            if(x.left.sValue < x.right.sValue) 
            {
                LeftHeapNode temp = x.left;
                  x.left = x.right;
                  x.right = temp;
            }
            x.sValue = x.right.sValue + 1;
        }        
        return x;
    }
 
    /** Function to delete minimum element **/
    public int deleteMin( )
    {
        if (isEmpty() )
            return -1;
        int minItem = root.element;
        root = merge(root.left, root.right);
        return minItem;
    }
 
    /** Inorder traversal **/
    public void inorder()
    {
        inorder(root);
        System.out.println();
    }
    private void inorder(LeftHeapNode r)
    {
        if (r != null)
        {
            inorder(r.left);
            System.out.print(r.element +" ");
            inorder(r.right);
        }
    }
}
 

非遞迴的merge實現：

    private LeftHeapNode mergeV2(LeftHeapNode h1, LeftHeapNode h2) {
        if (h1 == null) {
            return h2;
        }
        if (h2 == null) {
            return h1;
        }
        if (h1.element < h2.element ) {
            return mergeV2_1(h1, h2);
        } else {
            return mergeV2_1(h2, h1);
        }

    }

    private LeftHeapNode mergeV2_1(LeftHeapNode h1, LeftHeapNode h2) {
        if (h1.left == null) {
            h1.left = h2;
        } else {
            h1.right = mergeV2(h1.right,h2);
            if (h1.left.sValue < h1.right.sValue) {
                swapChildren(h1);
            }
            h1.sValue = h1.right.sValue + 1;
        }

        return h1;
    }

    private void swapChildren(LeftHeapNode  t) {
        LeftHeapNode temp = t.right;
        t.right = t.left;
        t.left = temp;
    }

 

引用：https://www.sanfoundry.com/java-program-implement-leftist-heap/

https://www.geeksforgeeks.org/leftist-tree-leftist-heap/

https://www.youtube.com/watch?v=y2mipTl823k

https://www.youtube.com/watch?v=RFCd3JUGhys

《資料結構與演算法（Java語言描述）第二版》