Finding the intersection of two arrays

Alexandr Melnik picture Alexandr Melnik · Oct 16, 2012 · Viewed 15.7k times · Source

My aim is to find out values of intersection of arrays a and b and store them into a new array c so the printout will be : 3,10,4,8. How do I assign given values to a 3rd array c ?

 public static void main(String[] args) {
        int a[] = {3, 10, 4, 2, 8};
        int[] b = {10, 4, 12, 3, 23, 1, 8};
        int[] c;
        int i=0;
         for(int f=0;f<a.length;f++){
              for(int k=0;k<b.length;k++){
                    if(a[f]==b[k]){
 //here should be a line that stores equal values of 2 arrays(a,b) into array c
            }
          }
        }
            for (int x=0; x<c.length; x++){
             System.out.println(c[i]);
            }
       }
  }

Answer

sakthisundar picture sakthisundar · Oct 16, 2012

This should be an easy way to do.

int a[] = {3, 10, 4, 2, 8};
int[] b = {10, 4, 12, 3, 23, 1, 8};
List<Integer> aList =  Arrays.asList(a);
List<Integer> bList =  Arrays.asList(b);
aList.retainAll(bList);
System.out.println(" a intersection b "+aList);
int[] c = aList.toArray(new int[0]);