Interview question: How to find the number of non-repeating numbers from 300 million integers

Recently saw an interview with Baidu: How to find the number of non-repeating numbers from 250 million integers

Write the following implementation, the time is slightly tight, the idea is slightly coarse, there are errors also please point out. Thank you.

int[] isrepeat = new Int[arr.length]; modified to int[] Isrepeat = new int[250000000];

Need to request the JVM 512M of memory

	public static int GetCount (int[] arr) {
		int norepeatcount = 0;//number of distinct digits
//		int repeatcount = 0;//repeats multiple times 
  int[] isrepeat = new Int[arr.length];
		for (int i:isrepeat) {
			isrepeat[i]=0;
		}
		Read in a number to see if the corresponding flag is 0, if 0,flag 1,count plus 1, if 1, do not process for
		(int i = 0; i < arr.length; i++) {
			int count = 1;
  
   if (Isrepeat[arr[i]] = = 0) {
				Isrepeat[arr[i]] + = count;
			} else if (Isrepeat[arr[i] > 0) {
				Isrepeat[arr [i]] + = count;
			}
		}
		for (int i:isrepeat) {
			if (i = = 1) {
				norepeatcount++;//returns the one that appears once
			} 
//			else if (i > 1) {
   
    // repeatcount++;////Returns the number of repeated occurrences // } } return norepeatcount; } public static void Main (string[] args) throws ParseException { int[] arr = {1, 2, 2, 3, 4, 5, 6, 7, 7, 8, 8, 8, 8, 9 , ten, ten}; System.out.println (GetCount (arr)); }