# 1979. Find Greatest Common Divisor of Array

Easy
Given an integer array `nums`, return the greatest common divisor of the smallest number and largest number in `nums`.
The greatest common divisor of two numbers is the largest positive integer that evenly divides both numbers.
Example 1:
Input: nums = [2,5,6,9,10]
Output:
2
Explanation:
The smallest number in nums is 2.
The largest number in nums is 10.
The greatest common divisor of 2 and 10 is 2.
Example 2:
Input: nums = [7,5,6,8,3]
Output:
1
Explanation:
The smallest number in nums is 3.
The largest number in nums is 8.
The greatest common divisor of 3 and 8 is 1.
Example 3:
Input: nums = [3,3]
Output:
3
Explanation:
The smallest number in nums is 3.
The largest number in nums is 3.
The greatest common divisor of 3 and 3 is 3.
Constraints:
• `2 <= nums.length <= 1000`
• `1 <= nums[i] <= 1000`

### 解題

func findGCD(nums []int) int {
min, max := nums[0], nums[0]
for _, num := range nums {
if num < min { min = num }
if num > max { max = num }
}
return gcd(min, max)
}
func gcd(a, b int) int {
if b == 0 { return a }
return gcd(b, a % b)
}