[349. Intersection of Two Arrays] (https://leetcode.com/problems/intersection-of-two-arrays/description/)
給定兩個數(shù)組，編寫一個函數(shù)來計算它們的交集耘分。
Example:
Given nums1 = [1, 2, 2, 1], nums2 = [2, 2], return [2].
Note:
每一個元素必須唯一.
結(jié)果可以是任意順序.
class Solution {
public int[] intersection(int[] nums1, int[] nums2) {
Set<Integer> set = new HashSet<>();
Arrays.sort(nums1);
for (int i = 0; i <nums2.length ; i++) {
if(binarySearch(nums1,nums2[i])>=0){
set.add(nums2[i]);
}
}
int[] result = new int[set.size()];
int k =0;
for (Integer i : set) {
result[k++] = i;
}
return result;
}
public static int binarySearch(int[] nums,int target){
int low = 0;
int high = nums.length-1;
while (low<=high){
int mid = low+(high-low)/2; //中值不能使用(low+high)/2，因為low+high 可能大于Integer.MAX_VALUE
if(nums[mid]>target){
high = mid -1;
}else if(nums[mid]<target){
low = mid +1;
}else{
return mid;
}
}
return -1;
}
}
