[leetcode 75] Sort Colors

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.

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

Follow up:

• Could you solve this problem without using the library's sort function?
• Could you come up with a one-pass algorithm using only O(1) constant space?

 

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]

Example 3:

Input: nums = [0] Output: [0]

Example 4:

Input: nums = [1] Output: [1]

 

Constraints:

• n == nums.length
• 1 <= n <= 300
• nums[i] is 0, 1, or 2.

문제 풀이:

- 쉬웠음

- 버블소트 사용

class Solution {
public:
    void sortColors(vector<int>& nums) {
     
        int len= nums.size();
        
        for(int i=0; i<len-1; i++){
            for(int j=0; j<len-1 - i; j++){
                if(nums[j] > nums[j+1]){
                    int tmp = nums[j];
                    nums[j] = nums[j+1];
                    nums[j+1] = tmp;
                }
            }
        }
    }
};