Split the array so that the sum of the numbers on one side of the split equals the sum of the numbers on the other side
The solution to this problem is easy, once you know the trick.

The trick, is to calculate the sum of all values then do add/subtract until they match... 

This is very different to what you have done, so it does not really make sense to review your algorithm, and then say 'you did it wrong'.

What I will do, is say your code is neat enough, and the logic you have done is visible enough, to make the algorithm clear. Even though it is not the best algorithm, you have implemented it well.

The problems with your algorithm are that you are doing the following:


you are calculating the sums of each side of the split each time
you are calculating all possible splits, even if you could identify a successful split sooner
The Pairs and other classes are overkill for the solution you could have....


So, the following code (on ideone too) makes the 'simple' solution 'obvious'....

public static bool CanArrayBeSplit(int[] intArray) {
    int sum = 0;
    foreach (int v in intArray) {
        sum += v;
    }
    int left = 0;
    int right = sum;
    for (int i = 0; left != right &amp;&amp; i &lt; intArray.Length; i++) {
        left += intArray[i];
        right -= intArray[i];
    }
    return left == right;
}
public static void Main()
{
    Console.WriteLine("Testing: " + CanArrayBeSplit(new int[]{1,2,3,4,5,6,7,8,9}));
    Console.WriteLine("Testing: " + CanArrayBeSplit(new int[]{1,2,3,4,5,6,7,8,9,45}));

}