Find out the 2nd largest number in a list of numbers

Assume the numbers are not sorted

int SecondLargestNumber(vector<int> v)
{
int LargestNumber = INT_MIN;
int SecondLargestNumber = INT_MIN;

        if (v.size() < 2)
        {
               return SecondLargestNumber;
        }

for (int index = 0; index < v.size(); index++)
{
if ((v[index] > LargestNumber) || (v[index] > SecondLargestNumber))
{
if ((v[index] < LargestNumber) && (v[index] > SecondLargestNumber))
{
SecondLargestNumber = v[index];
}

if (v[index] > LargestNumber)
{
SecondLargestNumber = LargestNumber;
LargestNumber = v[index];
}
}
}
   return SecondLargestNumber;
}