349. Intersection of Two Arrays

1. 问题描述

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

Example:

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

Note:

Each element in the result must be unique.
The result can be in any order.
Tags: Binary Search Hash Table Two Pointers Sort

Similar Problems: (E) Intersection of Two Arrays II

2. 解题思路

• 求两个数组中公有的数字
• 利用STL中的集合SET实现

3. 代码

class Solution {
public:
    vector<int> intersection(vector<int>& nums1, vector<int>& nums2) 
    {
        std::vector<int> tVec;
        if (nums1.empty() || nums2.empty())
        {
            return tVec;
        }
        std::set<int> tSet;
        std::set<int> tResultSet;
        for (int i=0; i<nums1.size(); i++)
        {
            tSet.insert(nums1.at(i));
        }
        for (int i=0; i<nums2.size(); i++)
        {
            if (tSet.find(nums2.at(i)) != tSet.end())
            {
                tResultSet.insert(nums2.at(i));
            }
        }
        std::set<int>::iterator it; 
        for(it = tResultSet.begin(); it != tResultSet.end(); it++)  
        {  
            tVec.push_back(*it); 
        }  
        return tVec;        
    }
};

4. 反思