写出二分查找的代码。

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【参考答案】

<pre><code>int b inary_search(int* arr, int key, int n)
{
int low = 0;
int h igh = n – 1 ;
int m id;
while (low <= high)
{
mid = (high + low) / 2;
if (arr[mid] > k)
high = mid -1 ;
else if (arr[mid] < k)
low = mid + 1;
else
return mid;
}
return -1;
}
</code></pre>

<pre><code> "“`