題目連結: https://leetcode.com/problems/sort-colors/

解法參考: https://leetcode.com/problems/sort-colors/discuss/1918849/100-Fastest-Swift-Solution-time%3A-O(n)-space%3A-O(1).

    func sortColors(_ nums: inout [Int]) {
    	var zeroIndex = 0
    	var twoIndex = nums.count - 1
    	var i = 0
    	while i <= twoIndex {
    		if nums[i] == 0, i > zeroIndex {
    			nums.swapAt(i, zeroIndex)
    			zeroIndex += 1
    		} else if nums[i] == 2, i < twoIndex {
    			nums.swapAt(i, twoIndex)
    			twoIndex -= 1
    		} else {
    			i += 1
    		}
    	}
    }