幾種經典排序演算法的JS實現方法+隨機洗牌演算法
阿新 • • 發佈:2019-01-07
一.氣泡排序
二.選擇排序
三.插入排序
四.希爾排序
六.快速排序
functionBubbleSort(array) { var length = array.length; for(var i = length - 1; i > 0; i--) { //用於縮小範圍 for(var j = 0; j < i; j++) { //在範圍內進行冒泡,在此範圍內最大的一個將冒到最後面 if(array[j] > array[j+1]) { var temp = array[j]; array[j] = array[j+1]; array[j+1] = temp; } } console.log(array); console.log("-----------------------------"); } return array; } var arr = [10,9,8,7,7,6,5,11,3]; var result = BubbleSort(arr); console.log(result); /* [ 9, 8, 7, 7, 6, 5, 10, 3, 11 ] ----------------------------- [ 8, 7, 7, 6, 5, 9, 3, 10, 11 ] ----------------------------- [ 7, 7, 6, 5, 8, 3, 9, 10, 11 ] ----------------------------- [ 7, 6, 5, 7, 3, 8, 9, 10, 11 ] ----------------------------- [ 6, 5, 7, 3, 7, 8, 9, 10, 11 ] ----------------------------- [ 5, 6, 3, 7, 7, 8, 9, 10, 11 ] ----------------------------- [ 5, 3, 6, 7, 7, 8, 9, 10, 11 ] ----------------------------- [ 3, 5, 6, 7, 7, 8, 9, 10, 11 ] ----------------------------- [ 3, 5, 6, 7, 7, 8, 9, 10, 11 ] */
二.選擇排序
functionSelectionSort(array) { var length = array.length; for(var i = 0; i < length; i++) { //縮小選擇的範圍 var min = array[i]; //假定範圍內第一個為最小值 var index = i; //記錄最小值的下標 for(var j = i + 1; j < length; j++) { //在範圍內選取最小值 if(array[j] < min) { min = array[j]; index = j; } } if(index != i) { //把範圍內最小值交換到範圍內第一個 var temp = array[i]; array[i] = array[index]; array[index] = temp; } console.log(array); console.log("---------------------"); } return array; } var arr = [ 1, 10, 100, 90, 65, 5, 4, 10, 2, 4 ]; var result = SelectionSort(arr); console.log(result); /* [ 1, 10, 100, 90, 65, 5, 4, 10, 2, 4 ] --------------------- [ 1, 2, 100, 90, 65, 5, 4, 10, 10, 4 ] --------------------- [ 1, 2, 4, 90, 65, 5, 100, 10, 10, 4 ] --------------------- [ 1, 2, 4, 4, 65, 5, 100, 10, 10, 90 ] --------------------- [ 1, 2, 4, 4, 5, 65, 100, 10, 10, 90 ] --------------------- [ 1, 2, 4, 4, 5, 10, 100, 65, 10, 90 ] --------------------- [ 1, 2, 4, 4, 5, 10, 10, 65, 100, 90 ] --------------------- [ 1, 2, 4, 4, 5, 10, 10, 65, 100, 90 ] --------------------- [ 1, 2, 4, 4, 5, 10, 10, 65, 90, 100 ] --------------------- [ 1, 2, 4, 4, 5, 10, 10, 65, 90, 100 ] --------------------- [ 1, 2, 4, 4, 5, 10, 10, 65, 90, 100 ] */
三.插入排序
functionInsertionSort(array) { var length = array.length; for(var i = 0; i < length - 1; i++) { //i代表已經排序好的序列最後一項下標 var insert = array[i+1]; var index = i + 1;//記錄要被插入的下標 for(var j = i; j >= 0; j--) { if(insert < array[j]) { //要插入的項比它小,往後移動 array[j+1] = array[j]; index = j; } } array[index] = insert; console.log(array); console.log("-----------------------"); } return array; } var arr = [100,90,80,62,80,8,1,2,39]; var result = InsertionSort(arr); console.log(result); /* [ 90, 100, 80, 62, 80, 8, 1, 2, 39 ] ----------------------- [ 80, 90, 100, 62, 80, 8, 1, 2, 39 ] ----------------------- [ 62, 80, 90, 100, 80, 8, 1, 2, 39 ] ----------------------- [ 62, 80, 80, 90, 100, 8, 1, 2, 39 ] ----------------------- [ 8, 62, 80, 80, 90, 100, 1, 2, 39 ] ----------------------- [ 1, 8, 62, 80, 80, 90, 100, 2, 39 ] ----------------------- [ 1, 2, 8, 62, 80, 80, 90, 100, 39 ] ----------------------- [ 1, 2, 8, 39, 62, 80, 80, 90, 100 ] ----------------------- [ 1, 2, 8, 39, 62, 80, 80, 90, 100 ] */
四.希爾排序
functionShellSort(array) { var length = array.length; var gap = Math.round(length / 2); while(gap > 0) { for(var i = gap; i < length; i++) { var insert = array[i]; var index = i; for(varj = i; j >= 0; j-=gap) { if(insert < array[j]) { array[j+gap] = array[j]; index = j; } } array[index] = insert; } console.log(array); console.log("-----------------------"); gap = Math.round(gap/2 - 0.1); } return array; } var arr = [ 13, 14, 94, 33, 82, 25, 59, 94, 65, 23, 45, 27, 73, 25, 39, 10 ]; var result = ShellSort(arr); console.log(result); /* [ 13, 14, 45, 27, 73, 25, 39, 10, 65, 23, 94, 33, 82, 25, 59, 94 ] ----------------------- [ 13, 14, 39, 10, 65, 23, 45, 27, 73, 25, 59, 33, 82, 25, 94, 94 ] ----------------------- [ 13, 10, 39, 14, 45, 23, 59, 25, 65, 25, 73, 27, 82, 33, 94, 94 ] ----------------------- [ 10, 13, 14, 23, 25, 25, 27, 33, 39, 45, 59, 65, 73, 82, 94, 94 ] ----------------------- [ 10, 13, 14, 23, 25, 25, 27, 33, 39, 45, 59, 65, 73, 82, 94, 94 ] */五.歸併排序
functionMergeSort(array) {
var length = array.length;
if(length <= 1) {
return array;
}else{
var num = Math.ceil(length/2);
var left = MergeSort(array.slice(0, num));
var right = MergeSort(array.slice(num, length));
return merge(left, right);
}
}
functionmerge(left, right) {
console.log(left);
console.log(right);
var a = newArray();
while(left.length > 0 && right.length > 0) {
if(left[0] <= right[0]) {
var temp = left.shift();
a.push(temp);
}else{
var temp = right.shift();
a.push(temp);
}
}
if(left.length > 0) {
a = a.concat(left);
}
if(right.length > 0) {
a = a.concat(right);
}
console.log(a);
console.log("-----------------------------");
return a;
}
var arr = [ 13, 14, 94, 33, 82, 25, 59, 94, 65, 23, 45, 27, 73, 25, 39, 10 ];
var result = MergeSort(arr);
console.log(result);
/*
[ 13 ]
[ 14 ]
[ 13, 14 ]
-----------------------------
[ 94 ]
[ 33 ]
[ 33, 94 ]
-----------------------------
[ 13, 14 ]
[ 33, 94 ]
[ 13, 14, 33, 94 ]
-----------------------------
[ 82 ]
[ 25 ]
[ 25, 82 ]
-----------------------------
[ 59 ]
[ 94 ]
[ 59, 94 ]
-----------------------------
[ 25, 82 ]
[ 59, 94 ]
[ 25, 59, 82, 94 ]
-----------------------------
[ 13, 14, 33, 94 ]
[ 25, 59, 82, 94 ]
[ 13, 14, 25, 33, 59, 82, 94, 94 ]
-----------------------------
[ 65 ]
[ 23 ]
[ 23, 65 ]
-----------------------------
[ 45 ]
[ 27 ]
[ 27, 45 ]
-----------------------------
[ 23, 65 ]
[ 27, 45 ]
[ 23, 27, 45, 65 ]
-----------------------------
[ 73 ]
[ 25 ]
[ 25, 73 ]
-----------------------------
[ 39 ]
[ 10 ]
[ 10, 39 ]
-----------------------------
[ 25, 73 ]
[ 10, 39 ]
[ 10, 25, 39, 73 ]
-----------------------------
[ 23, 27, 45, 65 ]
[ 10, 25, 39, 73 ]
[ 10, 23, 25, 27, 39, 45, 65, 73 ]
-----------------------------
[ 13, 14, 25, 33, 59, 82, 94, 94 ]
[ 10, 23, 25, 27, 39, 45, 65, 73 ]
[ 10, 13, 14, 23, 25, 25, 27, 33, 39, 45, 59, 65, 73, 82, 94, 94 ]
-----------------------------
[ 10, 13, 14, 23, 25, 25, 27, 33, 39, 45, 59, 65, 73, 82, 94, 94 ]
*/
六.快速排序
functionQuickSort(array) { var length = array.length; if(length <= 1) { return array; }else{ var smaller = []; var bigger = []; var base = [array[0]]; for(var i = 1; i < length; i++) { if(array[i] <= base[0]) { smaller.push(array[i]); }else{ bigger.push(array[i]); } } console.log(smaller.concat(base.concat(bigger))); console.log("-----------------------"); return QuickSort(smaller).concat(base.concat(QuickSort(bigger))); } } var arr = [ 8, 10, 100, 90, 65, 5, 4, 10, 2, 4 ]; var result = QuickSort(arr); console.log(result); /* [ 5, 4, 2, 4, 8, 10, 100, 90, 65, 10 ] ----------------------- [ 4, 2, 4, 5 ] ----------------------- [ 2, 4, 4 ] ----------------------- [ 2, 4 ] ----------------------- [ 10, 10, 100, 90, 65 ] ----------------------- [ 90, 65, 100 ] ----------------------- [ 65, 90 ] ----------------------- [ 2, 4, 4, 5, 8, 10, 10, 65, 90, 100 ] */
隨機洗牌演算法:
Array.prototype.shuffle = function() {
var input = this;
for(var i = input.length-1; i >=0; i--) {
var randomIndex = Math.floor(Math.random()*(i+1));
var itemAtIndex = input[randomIndex];
input[randomIndex] = input[i];
input[i] = itemAtIndex;
}
return input;
}
var tempArray = [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 ]
tempArray.shuffle();
// and the result is...
alert(tempArray);