[sort] sort algorithms #algorithm

sort.js

function bubbleSort(nums){
  if (!nums) return;
  
  for(let i = 0;i < nums.length; ++i){
    for(let j = 0;j < nums.length-1; ++j) {
      if (nums[j] > nums[j+1]) {
        let tmp = nums[j];
        nums[j] = nums[j+1];
        nums[j+1] = tmp;
      }
    }
  }
  
  return nums;
}

function selectionSort(nums) {
  if (!nums) return;
  
  for(let i = 0;i < nums.length; ++i){
    let min_i = i;
    let min_val = nums[i];
    for(let j = i;j < nums.length; ++j) {
      	if (nums[j] < min_val) {
          min_val = nums[j];
          min_i = j;
        }
    }
    let tmp = nums[i];
    nums[i] = nums[min_i];
    nums[min_i] = tmp;
  }
  return nums;
}

function insertion_sort(nums) {
  if (!nums) return;
  
  for (let i = 0;i < nums.length;++i) {
    let j = i-1;
    let value = nums[i];
    for (; j >= 0 && nums[j] > value; --j) {
      nums[j+1] = nums[j];
    }
    nums[j+1] = value;
  }
  return nums;
}

function quickSort(nums, left, right) {
  if (!nums || left >= right) return;
  let i = left, j = right, target = nums[left];
  while(i < j) {
    while(i < j && nums[j] >= target) --j;
    if(i < j) nums[i++] = nums[j];
    while(i < j && nums[i] <= target) ++i;
    if(i < j) nums[j--] = nums[i];
  }
  nums[i] = target;
  quickSort(nums, left, i-1);
  quickSort(nums, i+1, right);
}