349. Intersection of Two Arrays

原文题目：

349. Intersection of Two Arrays

读题：

该题用python来做的话将会很简单，具体可以参照另一篇博客python中求两个list的交集、并集、差集

而用C++的话想对绕一些，但也可以借助于STL中的set来做，集合做交集最适合了

python代码：

class Solution(object):
    def intersection(self, nums1, nums2):
        """
        :type nums1: List[int]
        :type nums2: List[int]
        :rtype: List[int]
        """
        intersec = [item for item in nums1 if item in nums2]
        return list(set(intersec))

if __name__ == '__main__':
    l1 =[1,2,3,3,2,1]
    l2 =[3,2,5]
    temp = Solution()
    print(temp.intersection(l1,l2))

C++代码：

class Solution 
{
public:
	vector<int> intersection(vector<int>& nums1, vector<int>& nums2) 
	{
		set <int> s1;
		set <int> s2;
		vector <int> result;
		set <int>::iterator ite1;
		set <int>::iterator ite2;
		int i =0;
		int j = 0;
		for(;i<nums1.size();i++)
		{
			s1.insert(nums1[i]);
		}
		for(;j<nums2.size();j++)
		{
			s2.insert(nums2[j]);
		}
		ite1 = s1.begin();
		ite2 = s2.begin();
		while(ite1 != s1.end()&&ite2 != s2.end())
		{
			if(*ite1 == *ite2)
			{
				result.push_back(*ite1);
				ite1++;
				ite2++;
			}
			else if(*ite1 < *ite2)
			{
				ite1++;
			}
			else
			{
				ite2++;
			}
		}
		return result;

	}
};

int main()
{
	
	Solution s;
	vector <int> vec1;
	vector <int> vec2;
	vector <int> temp;
	vec1.push_back(1);
	vec1.push_back(2);
	vec1.push_back(3);
	vec1.push_back(2);
	vec1.push_back(1);

	vec2.push_back(2);
	vec2.push_back(3);
	vec2.push_back(5);


	temp = s.intersection(vec1,vec2);
	
	for(int i =0; i < temp.size();i++)
	{
		cout << temp[i] << endl;
	}
	
	getchar();
}