题目描述
Given two arrays, write a function to compute their intersection.
Example1:
Input: nums1 = [1,2,2,1], nums2 = [2,2] Output: [2,2]
Example2:
Input: nums1 = [4,9,5], nums2 = [9,4,9,8,4] Output: [4,9]
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?
C++代码
class Solution {
public:
vector<int> intersect(vector<int>& nums1, vector<int>& nums2) {
sort(nums1.begin(), nums1.end());
sort(nums2.begin(), nums2.end());
vector<int> res;
int i = 0, j = 0;
while(i < nums1.size() && j < nums2.size()){
if(nums1[i] == nums2[j]){
res.push_back(nums1[i]);
i++;
j++;
}else if(nums1[i] < nums2[j]){
i++;
}else{
j++;
}
}
return res;
}
};
