基于二分查找的两个数组求合集

package test;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

public class Demo2 {
    
    public static List<Integer> intersection(int[] arr1, int[] arr2){
        List<Integer> list = new ArrayList<Integer>();
        for(int i : arr1){
            if(binarySearch(arr2, i))
                list.add(i);
        }
        return list;
    }
    
    public static boolean binarySearch(int[] i, int j){
        Arrays.sort(i);
        int low = 0;
        int high = i.length - 1;
        
        while(high >= low && low <= i.length - 1 && high <= i.length - 1){
            int middle = low + ((high - low) >> 1);
            if(j == i[middle]){
                return true;
            }else if(j > i[middle]){
                low = middle + 1;
            }else{
                high = middle - 1;
            }
        }
        return false;
    }
    
    public static void main(String[] args) {
        int[] arr1 = {1,2,4,5,6,7,11,34,56,55};
        int[] arr2 = {6,7,11,4,35,9,0,44};
        
        List<Integer> list = intersection(arr1, arr2);
        
        for(int i : list)
            System.out.print(i + ",");
        
    }

}