二分查找总是返回 -`

Question

我正在尝试使用 JS 实现二进制搜索，但它进入了无限循环。它不会返回位置。我不确定我在做什么错误。代码：function binarySearch(value, list) {    let initial = 0;    let end = list.length - 1;    let found = false;    let middle;    let position = -1;      while (found != true && initial <= end){      middle = Math.round(initial + end) / 2;      if (value == list[middle]) {      found = true;      position = middle;      } else if (value < list[middle]) end = middle - 1;      else initial = middle + 1;  }      console.log(position) ;    }binarySearch(3, [1, 3, 5, 6]);

Answer 1

你有middle = Math.round(initial + end) / 2;which 并不总是导致整数。

将其更改middle = Math.round((initial + end) / 2);为始终获取整数。

Answer 2

下面的代码总是正确的，因此是一个无限循环。

while (found != true && initial <= end)

    middle = Math.round(initial + end) / 2;

将代码放在大括号内

function binarySearch(value, list) {

  let initial = 0;

  let end = list.length - 1;

  let found = false;

  let middle;

  let position = -1;

  while (found != true && initial <= end){

    middle = Math.round((initial + end) / 2);

    if (value == list[middle]) {

    found = true;

    position = middle;

    } else if (value < list[middle]) end = middle - 1;

    else initial = middle + 1;

}

    return position;i

}