数组原地反转

[lewenweijia]

核心思想: 对撞指针, 数组项值互换

1. while 版本

   
   function reverse(nums) {
   let i = 0;
   let j = nums.length - 1;
   while (i < nums.length) {
   // boundary check
   if (i >= j) break;
   
   [nums[i], nums[j]] = [nums[j], nums[i]];
   
   i++;
   j--;
   }
   
   return nums;
   }

// reverse([]) -> [] // reverse([1,2,3,4]) -> [4,3,2,1]

2. `for` 版本
```js
function reverse(nums) {
  for (let i = 0, j = nums.length - 1; i < nums.length; i++, j--) {
      if (i >= j) break;

      [nums[i], nums[j]] = [nums[j], nums[i]];
    }
  }

  return nums;
}

[lewenweijia]

function reverse(arr) {
  let low = 0;
  let high = arr.length - 1;
  while (low < high) {
    [arr[low], arr[high]] = [arr[high], arr[low]];

    low++;
    high--;
  }

  return arr;
}