Leetcode 75. Sort Colors

Given an array with n objects colored red, white or blue, sort them so that objects of the same color are adjacent, with the colors in the order red, white and blue.

Here, we will use the integers 0, 1, and 2 to represent the color red, white, and blue respectively.

排列数组中的0,1.2

代码

public class Solution {
    public void sortColors(int[] nums) {
        int length = nums.length;
        int notRed = 0;
        int notBlue = length - 1;
        while(notRed < length && nums[notRed] == 0)
            notRed++;
        while(notBlue >= 0 && nums[notBlue] == 2)
            notBlue--;
        int i = notRed;
        while(i <= notBlue){
            int tem = nums[i];
            if(tem == 0)
            {
                swap(nums,i,notRed);
                notRed++;
                i++;
            }
            else if(tem == 2){
                swap(nums,i,notBlue);
                notBlue--;
            }
            else 
                i++;
        }
        
    }
    public void swap(int[] nums, int a, int b){
        int tem = nums[a];
        nums[a] = nums[b];
        nums[b] = tem;
    }
}