# Largest Number At Least Twice of Others

## Description

In a given integer array `nums`, there is always exactly one largest element.

Find whether the largest element in the array is at least twice as much as every other number in the array.

If it is, return the **index** of the largest element, otherwise return -1.

**Example 1:**

```
Input: nums = [3, 6, 1, 0]
Output: 1
Explanation: 6 is the largest integer, and for every other number in the array x,
6 is more than twice as big as x.  The index of value 6 is 1, so we return 1.
```

**Example 2:**

```
Input: nums = [1, 2, 3, 4]
Output: -1
Explanation: 4 isn't at least as big as twice the value of 3, so we return -1.
```

**Note:**

1. `nums` will have a length in the range `[1, 50]`.
2. Every `nums[i]` will be an integer in the range `[0, 99]`.

## Solutions

### My solution

```cpp
class Solution {
public:
    int dominantIndex(vector<int>& nums) {
        // max1: the largest number
        // max2: the second largest number
        // i1: the index of the largest number
        int max1 = -1, max2 = -1, i1;
        for(int i = 0; i < nums.size(); ++i){
            if(nums[i] > max1){
                max2 = max1;
                max1 = nums[i];
                i1 = i;
            }else if(nums[i] > max2){
                max2 = nums[i];
            }
        }
        return max1 < 2 * max2 ? -1 : i1;
    }
};
```


---

# 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://twchen.gitbook.io/leetcode/array/largest-number-at-least-twice-of-others.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.