1 // 推薦方法
 2 function getNoRepeatEle(n) {
 3     const arr = Array.from({ length: 100 }, (v, k) => k + 1);
 4     const result = [];
 5     let len = arr.length;
 6     for (let i = 0; i < n; i++) {
 7         const index = ~~(Math.random() * len) + i; // ~~雙按位非 取整
 8         if (result.includes(arr[index])) {
 9             continue;
10         }
11         result.push(arr[index]);
12         arr[index] = arr[i];
13         len--;
14     }
15     return result;
16 }
17 
18 // 變形 ，舉一反三
19 
20 function getNoRepeatEle2(n) {
21     const arr = Array.from({ length: 100 }, (v, k) => k + 1);
22     let result = [];
23     let len = arr.length;
24 
25     for (let i = 0; i < n; i++) {
26         let ran = Math.floor(Math.random() * (len - i));
27         if (result.includes(arr[ran])) {
28             continue;
29         }
30         result.push(arr[ran]);
31 
32         arr[ran] = arr[len - i - 1];
33     }
34 
35     return result;
36 }