[leetcode] 350. Intersection of Two Arrays II

题目：

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

Example:
Given nums1 = [1, 2, 2, 1], nums2 = [2, 2], return [2, 2].

Note:

• Each element in the result should appear as many times as it shows in both arrays.
• The result can be in any order.

Follow up:

• What if the given array is already sorted? How would you optimize your algorithm?
• What if nums1's size is small compared to nums2's size? Which algorithm is better?
• What if elements of nums2 are stored on disk, and the memory is limited such that you cannot load all elements into the memory at once?

代码：

class Solution {
public:
    vector<int> intersect(vector<int>& nums1, vector<int>& nums2) {
        vector<int> res;
        for(vector<int>::iterator i = nums1.begin(); i != nums1.end(); i++){
            for(vector<int>::iterator j = nums2.begin(); j != nums2.end(); j++){
                if((*i) == (*j)){
                    res.push_back((*i));
                    nums2.erase(j);
                    break;
                }
            }
        }
        return res;
    }
};