# Three Highest Numbers

Given an array, return the 3 max numbers in linear time, and constant space.

**The Idea:** Find the max 3 times. Every time, modify the contents of the array so that previous maximum is ignored. Restore the contents of the array in the end.

**Complexity:** O(n) time and O(1) space

```python
import sys

def three_highest(nums):
    max_i_1 = nums.index(max(nums))
    max_v_1 = nums[max_i_1]
    nums[max_i_1] = -sys.maxsize

    max_i_2 = nums.index(max(nums))
    max_v_2 = nums[max_i_2]
    nums[max_i_2] = -sys.maxsize

    max_i_3 = nums.index(max(nums))
    max_v_3 = nums[max_i_3]
    nums[max_i_3] = -sys.maxsize

    nums[max_i_1] = max_v_1
    nums[max_i_2] = max_v_2
    nums[max_i_3] = max_v_3

    return [max_v_1, max_v_2, max_v_3]


rand_ar = [9,4,89,6,7,5,781,964,7,8,5,201,20,9,7,1,2,35,612,30,7]
print(three_highest(rand_ar))
print(rand_ar)
```


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://maksimdan.gitbook.io/interview-practice-problems/leetcode_sessions/sorting-and-searching/three-highest-numbers.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.