Add two numbers with all corner case scenarios.
Corner cases
1. Both numbers are negative
a. Sum is negative - Will work fine
b. Sum is positive -
If the sum is positive or zero, this is only possible when the number is out of Max Integer range.
2. Both numbers are negative
a. Sum is positive
b. Sum is negative -
If the sum is negative, this is only possible when the number is out of Min Integer range.
public class AddTwoNumbers {
/**
* Adds two number.
*
* @param a
* @param b
* @return sum
*/
private static int add(int a, int b) {
int sum = a + b;
boolean flag = true;
if ((flag = a > 0 && b > 0) || (a < 0 && b < 0)) {
if ((flag && sum < 0) || (!flag && sum >= 0)) {
throw new ArithmeticException("Overflow");
}
}
return sum;
}
/**
* Driver method.
*
* @param args
*/
public static void main(String[] args) {
int sum1 = add(Integer.MIN_VALUE, 0);
System.out.println("Sum 1 " + sum1);
int sum2 = add(Integer.MAX_VALUE, -5);
System.out.println("Sum 2 " + sum2);
// Overflow due to both minimum negative values.
try {
add(Integer.MIN_VALUE, Integer.MIN_VALUE);
} catch (Exception e) {
System.err.println(e.getMessage());
}
// Overflow due to both maximum positive values.
try {
add(Integer.MAX_VALUE, Integer.MAX_VALUE);
} catch (Exception e) {
System.err.println(e.getMessage());
}
int sum5 = add(4, 5);
System.out.println("Sum 5 " + sum5);
int sum6 = add(-4, -5);
System.out.println("Sum 6 " + sum6);
}
}
