question
Given two arrays, write a function to compute their intersection.
Example 1:
Input: nums1 = [1,2,2,1], nums2 = [2,2]
Output: [2]
Example 2:
Input: nums1 = [4,9,5], nums2 = [9,4,9,8,4]
Output: [9,4]
Note:
Each element in the result must be unique.
The result can be in any order.
Ideas
1.set去重
2.hash表
class Solution {
public int[] intersection(int[] nums1, int[] nums2) {
int[] less=nums1.length<nums2.length?nums1:nums2;
int[] more=nums1.length>nums2.length?nums1:nums2 ;
HashSet<Integer> lessSet =new HashSet<Integer>();
for (int i = 0; i <less.length ; i++) {
lessSet.add(less[i]);
}
HashSet<Integer> moreSet =new HashSet<Integer>();
for(int i=0 ;i<more.length;i++){
if(lessSet.contains(more[i])){
moreSet.add(more[i]);
}
}
//Set 转为 数组
int size = moreSet.size(), k = 0;
int[] ans = new int[size];
for(int n : moreSet){
ans[k++] = n;
}
return ans;
}
}
