Overflow Smell

**Scenario.** You must count pairs i < j in an array of n = 100000 elements; the count can reach ~5·10^9. Your comparator uses a - b < 0 on values up to 10^9. What is the primary risk? **Which approach is the best fit? The program only needs to print the letter.** **A)** Neither — int handles 5·10^9 fine on 64-bit judges **B)** The count needs int64 (long long), and the subtracting comparator can overflow int **C)** Only the comparator is wrong; the count fits int **D)** Both are fine; overflow is only a Java problem