byte performs better than rune
IntuitionApproachComplexity
Time complexity:

Space complexity:
Code
# Intuition
<!-- Describe your first thoughts on how to solve this problem. -->

# Approach
<!-- Describe your approach to solving the problem. -->

# Complexity
- Time complexity:
<!-- Add your time complexity here, e.g. $$O(n)$$ -->

- Space complexity:
<!-- Add your space complexity here, e.g. $$O(n)$$ -->

# Code
```golang []
import "fmt"

func makeSmallestPalindrome(s string) string {
    r := []byte(s)

    for i, j := 0, len(r) - 1; i < j; i, j = i+1, j-1 {
        if r[i] < r[j] {
            r[j] = r[i]
        } else {
            r[i] = r[j]
        }
    }

    return string(r)
}
```
['Go']