算法题

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

  1. var getIntersectionNode = function(headA, headB) {
  2.     if (!headA || !headB) return null;
  3.     var head1 = headA;
  4.     var head2 = headB;
  5.     while(head1 !== head2) {
  6.         head1 = !head1 ? headB : head1.next;
  7.         head2 = !head2 ? headA : head2.next;
  9.     }
  10.     return head1
  11. };

解法:
双指针

手写题

写一个拖拽组件

  1. <!DOCTYPE html>
  2. <html lang="en">
  4.   <head>
  5.     <meta charset="UTF-8">
  6.     <meta http-equiv="X-UA-Compatible" content="IE=edge">
  7.     <meta name="viewport" content="width=device-width, initial-scale=1.0">
  8.     <title>Document</title>
  9.     <style>
  10.       body {
  11.         position: relative;
  12.         margin: 0;
  13.         padding: 0
  14.       }
  16.       #box {
  17.         position: absolute;
  18.         width: 120px;
  19.         height: 120px;
  20.         background-color: red;
  21.       }
  22.     </style>
  23.   </head>
  25.   <body>
  26.     <div id="box"></div>
  27.     <script>
  28.       window.onload = function () {
  29.         // drag处于绝对定位状态
  30.         let drag = document.getElementById("box");
  31.         drag.onmousedown = function (e) {
  32.           var e = e || window.event;
  33.           // 鼠标与拖拽元素边界的距离 = 鼠标与可视区边界的距离 - 拖拽元素与边界的距离
  34.           let diffX = e.clientX - drag.offsetLeft;
  35.           let diffY = e.clientY - drag.offsetTop;
  36.           drag.onmousemove = function (e) {
  37.             // 拖拽元素移动的距离 = 鼠标与可视区边界的距离 - 鼠标与拖拽元素边界的距离
  38.             let left = e.clientX - diffX;
  39.             let top = e.clientY - diffY;
  40.             // 避免拖拽出可视区
  41.             if (left < 0) {
  42.               left = 0;
  43.             } else if (left > window.innerWidth - drag.offsetWidth) {
  44.               left = window.innerWidth - drag.offsetWidth;
  45.             }
  46.             if (top < 0) {
  47.               top = 0;
  48.             } else if (top > window.innerHeight - drag.offsetHeight) {
  49.               top = window.innerHeight - drag.offsetHeight;
  50.             }
  51.             drag.style.left = left + "px";
  52.             drag.style.top = top + "px";
  53.           };
  54.           drag.onmouseup = function (e) {
  55.             this.onmousemove = null;
  56.             this.onmouseup = null;
  57.           };
  58.         };
  59.       };
  60.     </script>
  61.   </body>
  63. </html>

注意边界处理