88. Merge Sorted Array（LeetCode）

Given two sorted integer arrays nums1 and nums2, merge nums2 into nums1 as one sorted array.

Note:
You may assume that nums1 has enough space (size that is greater or equal to m + n) to hold additional elements from nums2. The number of elements initialized in nums1 and nums2 are m and n respectively.

class Solution {
public:
    void merge(vector<int>& nums1, int m, vector<int>& nums2, int n) {
        int i = 0;
        int j = 0;
        vector<int> vet;
        while (i <= m-1&&j <= n-1)
        {
            if (nums1[i] < nums2[j])
            {
                vet.push_back(nums1[i]);
                i++;
            }
            else
            {
                if (nums1[i] == nums2[j])
                {
                    vet.push_back(nums1[i]);
                    vet.push_back(nums2[j]);
                    i++;
                    j++;
                }
                else
                {
                    vet.push_back(nums2[j]);
                    j++;
                }
            }
        }
        while (i <= m-1)
        {
            vet.push_back(nums1[i]);
            i++;
        }
        while (j <= n-1)
        {
            vet.push_back(nums2[j]);
            j++;
        }
        nums1 = vet;
    }
};

class Solution {
public:
    void merge(vector<int>& nums1, int m, vector<int>& nums2, int n) {
        
        int curr = m+n-1, idx1 = m-1, idx2 = n-1;
        while (idx1 >= 0 || idx2 >= 0){
            if (idx1 >= 0 && idx2 >= 0){
                if (nums1[idx1] < nums2[idx2])
                    nums1[curr--] = nums2[idx2--];
                else
                    nums1[curr--] = nums1[idx1--];
            }
            else if (idx1 < 0)
                nums1[curr--] = nums2[idx2--];
            else
                nums1[curr--] = nums1[idx1--];
        }
    }
};