N-Repeated Element in Size 2N Array
In a array A of size 2N, there are N+1 unique elements, and exactly one of these elements is repeated N times.
Return the element repeated N times.
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Example 1:
Input: [1,2,3,3]
Output: 3
Example 2:
Input: [2,1,2,5,3,2]
Output: 2
Example 3:
Input: [5,1,5,2,5,3,5,4]
Output: 5
Note:
4 <= A.length <= 10000
0 <= A[i] < 10000
A.length is even
Java Solution:
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import java.util.HashMap;
import java.util.Map;
/**
* Created by bill on 2/18/19.
*/
public class Solution {
Map<Integer, Integer> myMap = new HashMap();
public int repeatedNTimes(int[] A) {
int N = A.length/2;
for (int ele: A) {
int tmp = 0;
if(!myMap.containsKey(ele)){
myMap.put(ele,1);
}
else{
tmp = myMap.get(ele) + 1;
myMap.replace(ele,tmp);
}
if(tmp == N){ return ele;}
}
return -1;
}
public static void main(String[] args) {
Solution mySolution = new Solution();
int [] array = {2,1,2,5,3,2};
int ret = mySolution.repeatedNTimes(array);
System.out.println(ret);
}
}
