## 冒泡排序 ``` var arr = [] for (let i = 0; i < 10000; i++) { arr.push(parseInt(Math.random()*10000)); } console.time('t'); bubbleSort(arr); console.timeEnd('t'); console.log(arr); // 2 1 4 3 5 6 function bubbleSort(arr) { for (let i = 0; i < arr.length; i++) { for (let j = 0; j < arr.length - i - 1; j++) { if (arr[j] > arr[j+1]) { let tmp = arr[j]; arr[j] = arr[j+1]; arr[j+1] = tmp; } } } } ``` <br> ## 原生排序 ``` var arr = [] for (let i = 0; i < 10000; i++) { arr.push(parseInt(Math.random()*10000)); } console.time('t'); arr.sort() console.timeEnd('t'); console.log(arr); ``` <br> ## 快速排序 ``` var arr = [] for (let i = 0; i < 10000; i++) { arr.push(parseInt(Math.random()*10000)); } // console.log(arr); console.time('t'); let arr2 = quickSort(arr); console.timeEnd('t'); console.log(arr2); // 快速排序初級版 function quickSort(arr) { //如果數組<=1,則直接返回 if (arr.length <= 1) { return arr; } var pivotIndex = Math.floor(arr.length / 2); //找基準，并把基準從原數組刪除 var pivot = arr.splice(pivotIndex, 1)[0]; //定義左右數組 var left = []; var right = []; //比基準小的放在left，比基準大的放在right for (var i = 0; i < arr.length; i++) { if (arr[i] <= pivot) { left.push(arr[i]); } else { right.push(arr[i]); } } //遞歸 return quickSort(left).concat([pivot]).concat(quickSort(right)); } ```