【js基础】js排序方法——快排+堆排+插排+选择排

Array.prototype.fastSort = function(){
var arr = this; function sort(left, right, arr){
if( left >= right){
return;
}
var key = arr[left];
var i = left;
var j = right; while(i < j){
while(i < j && arr[j] >= key){
j--;
}
arr[i] = arr[j];
while(i < j && arr[i] <= key){
i++;
}
arr[j] = arr[i];
}
arr[i] = key;
sort(left, i - 1, arr);
sort(i + 1, right, arr);
} sort(0, arr.length - 1, arr); return arr;
}

Array.prototype.insertSort = function(){
var arr = this;
var len = arr.length;
for(var i = 1; i < len; i ++ ){
var j = i - 1;
var tmp = arr[i];
while(j >= 0 && tmp < arr[j]){
arr[j + 1] = arr[j];
j--;
}
if(j != i - 1){
arr[j + 1] = tmp;
}
}
return arr;
}

Array.prototype.selectSort = function(){
var arr = this;
var len = arr.length;
var min;
var tmp;
for(var i = 0; i < len - 1; i ++ ){
min = i;
for(var j = i + 1; j < len; j++){
if(arr[min] > arr[j]){
min = j;
}
}
if(min != i){
tmp = arr[min];
arr[min] = arr[i];
arr[i] = tmp;
}
}
return arr;
}

Array.prototype.swap = function(i, j){
var tmp = this[i];
this[i] = this[j];
this[j] = tmp;
} //大顶堆
Array.prototype.buildMaxHeap = function(){
for(var i = Math.floor(this.length/2) - 1; i >= 0; i--){
this.heapAdjust(i, this.length);
}
}; //调整堆
Array.prototype.heapAdjust = function(i, j){
var max = i;
var left = 2 * i + 1;
var right = 2 * i + 2;
if(left < j && this[max] < this[left]){
max = left;
}
if(right < j && this[max] < this[right]){
max = right;
}
if(max != i){
this.swap(i,max);
this.heapAdjust(max,j);
};
} //堆排序
Array.prototype.heapSort = function(){
this.buildMaxHeap();
for(var i = this.length - 1; i >= 0 ; i--){
this.swap(0, i);
this.heapAdjust(0, i);
}
return this;
};