```
Arrays.sort(A);
```

for(int i=0;i<A.length-1;i+=3){

if(A[i]!=A[i+1]){

return A[i];

}

}

return A[A.length-1];

```
Arrays.sort(A);
```

for(int i=0;i<A.length-1;i+=3){

if(A[i]!=A[i+1]){

return A[i];

}

}

return A[A.length-1];

"Note: Your algorithm should have a linear runtime complexity."

Sorting is O(n*log(n)) always, so your solution works, but does not meet the required criteria.