leetcode上第349号问题:Intersection of Two Arrays
给定两个数组,编写一个函数来计算它们的交集。 示例 1: 输入: nums1 = [1,2,2,1], nums2 = [2,2] 输出: [2] 示例 2: 输入: nums1 = [4,9,5], nums2 = [9,4,9,8,4] 输出: [9,4] 说明:
容器类set的使用。
1// 349. Intersection of Two Arrays
2// https://leetcode.com/problems/intersection-of-two-arrays/description/
3// 时间复杂度: O(nlogn)
4// 空间复杂度: O(n)
5class Solution {
6public:
7 vector<int> intersection(vector<int>& nums1, vector<int>& nums2) {
8
9 set<int> record;
10 for( int i = 0 ; i < nums1.size() ; i ++ ){
11 record.insert(nums1[i]);
12 }
13
14 set<int> resultSet;
15 for( int i = 0 ; i < nums2.size() ; i ++ ){
16 if(record.find(nums2[i]) != record.end()){
17 resultSet.insert(nums2[i]);
18 }
19 }
20
21 vector<int> resultVector;
22 for(set<int>::iterator iter = resultSet.begin(); iter != resultSet.end(); iter ++ ){
23 resultVector.push_back(*iter);
24 }
25
26 return resultVector;
27 }
28};
1// 349. Intersection of Two Arrays
2// https://leetcode.com/problems/intersection-of-two-arrays/description/
3// 时间复杂度: O(nlogn)
4// 空间复杂度: O(n)
5class Solution {
6public:
7 vector<int> intersection(vector<int>& nums1, vector<int>& nums2) {
8
9 set<int> record(nums1.begin(), nums1.end());
10
11 set<int> resultSet;
12 for( int i = 0 ; i < nums2.size() ; i ++ )
13 if( record.find(nums2[i]) != record.end() )
14 resultSet.insert( nums2[i] );
15
16 return vector<int>(resultSet.begin(), resultSet.end());
17 }
18};