# 75. Sort Colors

Medium
Given an array `nums` with `n` objects colored red, white, or blue, sort them in-place so that objects of the same color are adjacent, with the colors in the order red, white, and blue.
We will use the integers `0`, `1`, and `2` to represent the color red, white, and blue, respectively.
You must solve this problem without using the library's sort function.
Example 1:
Input: nums = [2,0,2,1,1,0]
Output:
[0,0,1,1,2,2]
Example 2:
Input: nums = [2,0,1]
Output:
[0,1,2]
Constraints:
• `n == nums.length`
• `1 <= n <= 300`
• `nums[i]` is either `0`, `1`, or `2`.
Follow up: Could you come up with a one-pass algorithm using only constant extra space?

### 解題

Runtime: 0 ms, faster than 100%
Memory Usage: 2.1 MB, less than 72.27%
func sortColors(nums []int) {
count := make([]int, 3)
for _, num := range nums {
count[num]++
}
index := 0
for i:=0; i<count[0]; i++ {
nums[index] = 0
index++
}
for i:=0; i<count[1]; i++ {
nums[index] = 1
index++
}
for i:=0; i<count[2]; i++ {
nums[index] = 2
index++
}
}