126. Add Signed and Unsigned Integers Safely

You are given two inputs:

• int8_t a (signed 8-bit)
• uint8_t b (unsigned 8-bit)

Your task is to:

• Perform the addition of a + b safely, ensuring that if a is negative, the final result is still correctly signed
• Return the result as a signed 16-bit integer (int16_t) so the overflow can be observed
   

Example-1

Input: a = -10, b = 20
Output: 10

Example-2

Input: a = 10, b = 250
Output: 260

Example-3

Input: a = -128, b = 255
Output: 127