【leetcode】双指针：移动零 and 复写零

1.移动零

class Solution {
public:
    void moveZeroes(vector<int>& nums) {
       for (int cur = 0, dest = -1; cur < nums.size(); cur++)
            if (nums[cur] != 0)
                swap(nums[++dest], nums[cur]);
    }
};

class Solution {
public:
    void moveZeroes(vector<int>& nums) {
        int cur = 0, dest = -1, n = nums.size();
       while(cur < n)
        {
            if(nums[cur])
            {
                swap(nums[cur++], nums[++dest]);
              
            }
            else
            {
                  cur++;
            }
        }
    }
};

2.复写零

class Solution 
{
public:
    void duplicateZeros(vector<int>& nums) 
    {
        int cur = 0, dest = -1, n = nums.size();
        while(cur < n)
        {
            if(nums[cur]) dest++;
            else  dest += 2;
          
            if(dest >= n - 1) break;
            cur++; 
        }
        if(dest == n)
        {
            nums[n - 1] = 0;
            cur--; 
            dest -= 2;
        }
        while(cur >= 0)
        {
            if(nums[cur])
            {
                nums[dest--] = nums[cur--];
            }
            else
            {
                nums[dest--] = 0;
                nums[dest--] = 0;
                cur--;
            }
        }
    }
};