I'm trying to remove duplicate numbers from an array using a method but, unfortunately I can not solve it. This what I have done so far:
//method code
public static int[] removeDuplicates(int[] input){
int []r=new int[input.length];
for (int i = 0; i < input.length; i++) {
for (int j = 0; j < input.length; j++) {
if ((input[i]==input[j]) && (i != j)) {
return r;
}
}
}
return r;
}
The easiest thing to do is add all elements in a Set.
public static int[] removeDuplicates(int[] input){
Set<Integer> set = new HashSet<Integer>();
for (int i = 0; i < input.length; i++) {
set.add(input[i]);
}
//by adding all elements in the Set, the duplicates where removed.
int[] array = new int[set.size()];
int i = 0;
for (Integer num : set) {
array[i++] = num;
}
return array;
}
You may do it this way:
public static int[] removeDuplicates(int[] input){
boolean[] duplicate = new boolean[input.length];
int dups = 0;
for (int i = 0; i < input.length; i++) {
if(duplicate[i])
continue;
for (int j = i + 1; j < input.length; j++) {
if ((input[i]==input[j])) {
duplicate[j] = true; // j is duplicate
++dups;
}
}
}
int[] r = new int[input.length] - dups;
int index = 0;
for(int i = 0; i < input.length; ++i)
r[index++] = input[i];
return r;
}
It can also be done in O(n log n). C++ code
If you don't want duplicates in your collection, well you shouldn't be using an Array in the first place. Use a set instead and you will never duplicates to remove in the first place.
If you only "sometimes" want no duplicates, well you better explain your situation further.
main(String[] argv)". There are such things as input data, and it does not always come in the form most convenient to the program.
containsmethod.