int a;
int b;
 
average_two_ints() {
 
(a + b) / 2;
// What if (a + b) > INT_MAX ?  Overflow!
// This does not do what you want 100% of the time
 
(a + b) >> 1;
// Shifting...
//   - Takes care of the sign bit by shifting it in ( http://en.wikipedia.org/wiki/Division_by_two#Binary
//   - Shifts the lsb out to take care of units place ( oddint/2 == floor(oddint/2) )
// Does what you want 100% of the time (caveat: see your language spec (looking at you Java))
 
}
 
// Use practices that causes your code to be correct 100% of the time in your implementation
// How would you catch something subtle like this?
// Testing, testing, testing, repeatable testing, testing, test cases, testing
// Good test cases are designed to ensure something works as expected for all input
// Testing all input is unfeasible; average cases and edge cases