Leetcode question brushing record ｜ 283_ Move zero

author github link ： github link

Force to buckle 283 topic

type ： Array question

subject ：

Given an array nums, Write a function that will 0 Move to end of array , While maintaining the relative order of non-zero elements .

Please note that , You must operate on the array in place without copying it .

Example 1

 Input : nums = [0,1,0,3,12]
 Output : [1,3,12,0,0]

Example 2

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

Their thinking

Train of thought reminder ： Double pointer （ Fast pointer and slow pointer ）
Train of thought details ：

1. Define two pointers , for example fast and slow
2. Place both pointers at the beginning of the array , That is to say, make fast = 0,slow = 0
3. The fast pointer traverses the entire array in turn , When to take action ？
4. When the fast pointer encounters It's not equal to 0 When the number of , Take action at this time ： Point the slow pointer to the value of the position and the fast pointer to the value of the position In exchange for
5. After switching positions , Move the position of the slow pointer to the next position +1
6. repeat 4～5 Until the traversal is complete

c++ edition

class Solution {
    
public:
    void moveZeroes(vector<int>& nums) {
    
        int n = nums.size();
        int fast = 0,slow = 0;
        for(int i = 0;i<n;i++){
    
            if(nums[i]!=0){
    
                swap(nums[fast], nums[slow]);
                slow++;
            }
            fast++;
        }
        
    }
};

python edition

class Solution:
    def moveZeroes(self, nums: List[int]) -> None:
        """ Do not return anything, modify nums in-place instead. """
        fast=0
        slow=0
        for i in range(0,len(nums)):
            if nums[i]!=0:
                nums[fast],nums[slow] = nums[slow],nums[fast]
                slow = slow+1
            fast = fast+1