import java.util.*;

public class FindMostInArray {
    public static void main(String args[]){
        int[] intArray = {1,2,2,3,4,4,5,6,7,7,8,9};
        List<Integer> list = new ArrayList<Integer> ();
        
        String str = "";
        
        for(int i=0; i<intArray.length; i++){
            str += String.valueOf(intArray[i]);
        }

        int MaxCount = 0;
        
        for(int i=0; i<intArray.length; i++){
            String tempString = str.replaceAll(String.valueOf(intArray[i]), "");
            int tempCount = str.length() - tempString.length();
            
            if (tempCount > MaxCount){
                list.clear();
                list.add(intArray[i]);
                MaxCount = tempCount;
            }
            else if((tempCount == MaxCount) && (!list.contains(intArray[i]))){
                list.add(intArray[i]);
            }
        }
        
        System.out.println("The most repeat number is: "+ MaxCount +"\nThe duplicated elements are: "+ list.toString());
    }
}

------解决方案--------------------
import java.util.HashMap;
import java.util.Iterator;

public class OnlyOne {
	public static void main(String[] args) {
		int[] arr = {1,2,3,4,5,3,3,1,2,1,1,6,7,5,7};
		HashMap<Integer, Integer> hm = new HashMap<Integer, Integer>();
		for(int i=0; i<arr.length; i++){
			hm.put(arr[i], hm.get(arr[i])==null?1:hm.get(arr[i])+1);
		}
		Iterator<Integer> iter = hm.keySet().iterator();
		for(int i=iter.next(); iter.hasNext(); i=iter.next()){
			if(hm.get(i) == 1){
				System.out.println(i);
			}
		}
	}
}

------解决方案--------------------
直方图统计
hist[arr[i]]=hist[arr[i]]+1；


------解决方案--------------------
6楼的就可以了
觉得不好的话，可以把HashMap改成int[50]，然后参考7楼

------解决方案--------------------
代码：
Java code
import java.util.Arrays; 
  
 public class Test { 
  
 	public static void main(String[] args) { 
 		int[] ta = {1, 2, 3, 4, 5, 3, 3, 1, 2, 1, 1, 6, 7, 5, 7}; 
 		int[] r = test(ta, 1); 
 		System.out.println(Arrays.toString(r)); 
 	} 
  
 	public static int[] test(int[] array, int count) { 
 		if (array == null || array.length == 0 || count  <= 0) return null; 
 		int max = array[0]; 
 		for (int i = array.length - 1, j = 0; i > 0;) { 
 			j = array[i--]; 
 			if (j  < 0) return null; 
 			if (max  < j) max = j; 
 		} 
 		int[] t = new int[max + 1]; 
 		for (int i = array.length - 1; i >= 0;) { 
 			t[array[i--]]++; 
 		} 
 		int[] r = new int[max + 1]; 
 		int j = 0; 
 		for (int i = t.length - 1; i >= 0; i--) { 
 			if (t[i] == count) r[j++] = i; 
 		} 
 		return Arrays.copyOf(r, j); 
 	} 
  
 }