https://leetcode-cn.com/problems/intersection-of-two-linked-lists/

    1. /**
    2.  * Definition for singly-linked list.
    3.  * class ListNode {
    4.  *     val: number
    5.  *     next: ListNode | null
    6.  *     constructor(val?: number, next?: ListNode | null) {
    7.  *         this.val = (val===undefined ? 0 : val)
    8.  *         this.next = (next===undefined ? null : next)
    9.  *     }
    10.  * }
    11.  */
    13. // a:1->2->3->4->5->6->null->9->5->6->null
    14. // b:9->5->6->null->1->2->3->4->5->6->null
    16. function getIntersectionNode(headA: ListNode | null, headB: ListNode | null): ListNode | null {
    17.   if (!headA || !headB) return null;
    18.   let a = headA, b = headB;
    19.   while (a !== b) {
    20.     a = a ? a.next : headB;
    21.     b = b ? b.next : headA
    22.   }
    23.   return a;
    24. };
    1. <!DOCTYPE html>
    2. <html lang="en">
    3.   <head>
    4.     <meta charset="UTF-8">
    5.     <meta http-equiv="X-UA-Compatible" content="IE=edge">
    6.     <meta name="viewport" content="width=device-width, initial-scale=1.0">
    7.     <title>拖拽的DIV</title>
    8.   </head>
    9.   <body>
    10.     <div id="box"></div>
    11.   </body>
    12. </html>
    13. <style>
    14. * {
    15.   margin: 0;
    16.   padding: 0;
    17. }
    19. #box {
    20.   position: absolute;
    21.   left: 50%;
    22.   top: 50%;
    23.   width: 60px;
    24.   height: 60px;
    25.   border-radius: 50%;
    26.   background: blueviolet;
    27.   cursor: move;
    28. }
    29. </style>
    30. <script>
    31.   const box = document.getElementById('box');
    32.   let offsetX, offsetY;
    33.   box.onmousedown = function (e) {
    34.     const { left, top } = box.getBoundingClientRect();
    35.     offsetX = e.clientX - left;
    36.     offsetY = e.clientY - top;
    37.     document.onmousemove = handleMove;
    38.     document.onmouseup = handleStop;
    39.   }
    41.   function handleMove(e) {
    42.     let left = e.clientX - offsetX;
    43.     let top = e.clientY - offsetY;
    44.     const width = document.documentElement.clientWidth - box.offsetWidth;
    45.     const height = document.documentElement.clientHeight - box.offsetHeight;
    46.     // 处理边界
    47.     if (left < 0) left = 0;
    48.     if (left > width) left = width;
    49.     if (top < 0) top = 0;
    50.     if (top > height) top = height;
    51.     box.style.left = `${left}px`;
    52.     box.style.top = `${top}px`;
    53.   }
    55.   function handleStop() {
    56.     document.onmouseup = null
    57.     document.onmousemove = null
    58.   }
    59. </script>