function selectSort(arr) {
const len = arr.length;
for (let i = 0; i < len; i++) {
var minIndex = i;
for (let j = i + 1; j < len; j++) {
if (arr[j] < arr[minIndex]) {
minIndex = j;
}
}
[arr[i], arr[minIndex]] = [arr[minIndex], arr[i]];
}
return arr;
}
####insert sort
function insertSort(arr) {
var len = arr.length;
var preIndex, current;
for (let i = 1; i < len; i++) {
preIndex = i - 1;
current = arr[i];
while (preIndex >= 0 && arr[preIndex] > current) {
arr[preIndex + 1] = arr[preIndex];
preIndex--;
}
arr[preIndex + 1] = current;
}
return arr;
}
function mergeSort(arr) {
var len = arr.length;
if (len < 2) {
return arr;
}
var middle = Math.floor(len / 2),
left = arr.slice(0, middle),
right = arr.slice(middle);
return merge(mergeSort(left), mergeSort(right));
}
function merge(left, right) {
var result = [];
while (left.length && right.length) {
if (left[0] < right[0]) {
result.push(left.shift());
} else {
result.push(right.shift());
}
}
while (left.length) {
result.push(left.shift());
}
while (right.length) {
result.push(right.shift());
}
return result;
}
function partition(arr, left, right) {
var pivot = left,
index = pivot + 1;
for (let i = index; i <= right; i++) {
if (arr[i] < arr[pivot]) {
swap(arr, i, index);
index++;
}
}
swap(arr, pivot, index - 1);
return index - 1;
}
function swap(arr, i, j) {
[arr[i], arr[j]] = [arr[j], arr[i]];
}
function quickSort(arr, left, right) {
var partitionIndex,
left = typeof left != "number" ? 0 : left,
right = typeof right != "number" ? arr.length - 1 : right;
if (left < right) {
partitionIndex = partition(arr, left, right);
quickSort(arr, left, partitionIndex - 1);
quickSort(arr, partitionIndex + 1, right);
}
return arr;
}