How to find the first non-repeated element in an unsorted array?

Question

Given an unsorted array which has a number in the majority (a number appears more than 50% in the array), how to find that number?

Answer 1

static int FirstNonRepeated(IEnumerable<int> iArr)
{
    Dictionary<int, int> dict = new Dictionary<int,int>();
    int count = 0;

    int firstNumber = -1;

    foreach (int i in iArr)
    {           
        if (dict.ContainsKey(i))
        {
            dict.TryGetValue(i, out count);
            dict[i] = count++;              
        }
        else
        {
            dict.Add(i, 1);
        }

    }

    foreach (KeyValuePair<int, int> kp in dict)
    {
        if (kp.Value.Equals(1))
        {
            firstNumber = kp.Key;
            break;
        }
    }

    return firstNumber;
}

Answer 2

Algorithm :
1: scan the array from left to right.
1.a: Make count array to each element of given array.
2. scan count array from left to right.
2.a check current count array element is 1
2.b Print that element and stop
3: exit.