UVa 11479 - Is this the easiest problem?

Summary
Check if three supposed triangle sides compose a valid triangle and if it does, say what type of triangle it forms.

Explanation
A valid triangle has all sides greater than 0 and for any given a, b and c sides, the following is true: $$|b - c|  < a < b + c$$

The difference between triangle types is

Equilateral: $$a = b = c$$

Isosleces: $$a = b != c $$   ( or )    $$  a = c != b$$     ( or )    $$ b = c != a $$

Scalene: $$a!= b != c$$

Data type
Instructions say your program must read "three 32 bit signed integer" (int). Don't forget that you will have to sum the values, so if you use int, you will be able to receive the values but it will overflow when you sum them. You must use long int for your input variables.

Input
10 3 4 -5 5 3 5 6 2 9 1 2 7 2147483647 2147483647 2147483647 6 0 6 2 6 1 8 7 9 5 5 5 3 7 5

Output
Case 1: Invalid Case 2: Isosceles Case 3: Invalid Case 4: Invalid Case 5: Equilateral Case 6: Invalid Case 7: Invalid Case 8: Scalene Case 9: Equilateral Case 10: Scalene

Solution

 * C: http://pastebin.com/KQTEF54g
 * Code All the Problems