350. Intersection of Two Arrays II

Problem:

Given two arrays, write a function to compute their intersection.

Example 1:

Input: nums1 = [1,2,2,1], nums2 = [2,2]
Output: [2]

Example 2:

Input: nums1 = [4,9,5], nums2 = [9,4,9,8,4]
Output: [9,4]

Note:

• Each element in the result must be unique.
• The result can be in any order.

思路：

Solution (C++):

vector<int> intersect(vector<int>& nums1, vector<int>& nums2) {
    if (nums1.empty() || nums2.empty())  return vector<int>{};
    int m = nums1.size(), n = nums2.size(), inter = 0;
    vector<int> res;
    if (m <= n) {
        for (int i = 0; i < m; ++i) {
            for (int j = 0; j < n-inter; ++j) {
                if (nums1[i] == nums2[j])  { 
                    res.push_back(nums1[i]); 
                    swap(nums2[j], nums2[n-1-inter]);
                    inter++;
                    break;
                }
            }
        }
    } else {
        for (int i = 0; i < n; ++i) {
            for (int j = 0; j < m-inter; ++j) {
                if (nums2[i] == nums1[j])  { 
                    res.push_back(nums2[i]); 
                    swap(nums1[j], nums1[m-1-inter]);
                    inter++;
                    break;
                }
            }
        }
    }
    return res;
}

性能：

Runtime: 16 ms  Memory Usage: 6.6 MB

思路：

Solution (C++):

性能：

Runtime: ms  Memory Usage: MB