Majority Element Solution

 Given an array A of N elements. Find the majority element in the array. A majority element in an array A of size N is an element that appears more than N/2 times in the array.

 

Example 1:

Input:
N = 3 
A[] = {1,2,3} 
Output:
-1
Explanation:
Since, each element in 
{1,2,3} appears only once so there 
is no majority element.

Example 2:

Input:
N = 5 
A[] = {3,1,3,3,2} 
Output:
3
Explanation:
Since, 3 is present more
than N/2 times, so it is 
the majority element.

Your Task:
The task is to complete the function majorityElement() which returns the majority element in the array. If no majority exists, return -1.
 

Expected Time Complexity: O(N).
Expected Auxiliary Space: O(1).
 

Constraints:
1 <= N <= 107
0 <= Ai <= 106

Solution

class Solution
{
    static int majorityElement(int a[], int size)
    {
        // your code here
        int ans =-1;
        int[] me = new int[10000000];
        
        for(int i=0;i<size;i++) 
            me[a[i]]++;
            
        if(size==1) 
            return a[0];
        
        for(int i=0;i<size+1;i++) 
            if(me[i]>size/2) 
                ans = i;
                
        return ans;
    }
}